DICKARENTZ

With contributions by:

Bob Herbst Sandy King Stan Klimek Mark Nelson Keith Schreiber

AMSTERDAM BOSTON HEIDELBERG LONDON NEW YORK OXFORD PARIS SAN DIEGO SAN FRANCISCO SINGAPORE SYDNEY TOKYO ELSEVIER Focal Press is an imprint of Elsevier Copyright C 2005, Dick Arentz. All rights reserved. All photographs 8 Dick Arentz, unless otherwise specified.

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Printed in China To Phil Davis Professor Emeritus, University of Michigan Teacher, Mentor, and Friend

In 1970, I was an Assistant Professor at the University of Michigan in a discipline far removed from art or photography. I was also an advanced amateur photographer, having taken a number of Ansel Adams workshops. Phil Davis was, at that time, head of the Department of Photography. One winter weekend, I hitched a ride with Phil and his students to a Society of Photographic Education meeting in Rochester, NY. For some reason, Phil and I were billeted at a motel removed from the rest. A typical Rochester snowfall came to bury the city, completely removing parked cars from sight, and confining us to our rooms . . . and the bar. It was there that Phil finally suggested that I knew practically nothing about photography. If, however, I would be willing to make the effort, he would tutor me. Almost thirty-five years later, Phil, the source of one of the most significant changes in my life, is still my teacher. A good portion of this text, and the entire basis for Part Two, come from Phil’s research, his book Beyond the Zone System, and his Plotter ProgramR. He has read and, mercifully, graciously criticized only those sections of this book. Preface to the Second Edition and Acknowledgments xiv Preface and Acknowledgments xvii Introduction xx

PARTONE THE PROCESS 1

CHAPTER 1 PlATiNUM ANd PA1lAdiUM 3 Platinum Printing in the Twentieth Century 4 The PlatinurdPalladium and Silver Processes Compared 4 Platinum and Palladium Compared 5

CHAPTER 2 SETTiNCj up A LAbORATORy 7 The Wet Space and Coating Area 8 The Drying and Exposure Area 9 Materials 10 The Wet Area 10 The Coating Area 10 The Exposure and Finishing Area 10 Contact Printing Frames 11 The Ultraviolet Light Source 12 The Sun 12 Mercury Vapor, Metal Halide, and UV Fluorescent Lights 13 Commercial Plate Burner 13 Densitometers 13 Modifying a Light Meter 13 Inexpensive Table-Model Densitometers 14 Hand-Held Densitometers 14 The Professional Models 14

CHAPTER3 ThE NECjATivE 15 Photographic Sensitometry 16 Definitions 17 Transmission Densities 17 The Logarithmic System 17 The Density Range for a Platinum or Palladium Negative 18 Negative Contrast Versus Negative Density 18 Exposure 18 Development 19 The Negative Density Range 19

vi CONTENTS vii

Exposing and Developing the Platinum or Palladiuin Negative 20 Zone System Development Compared to Subject Brightness Range 21 Development for Subject Brightness Ranges 21 Average Gradient 22 Effective Film Speed 22 Characteristics of the Platinum/Palladium Negative 24 Sharpness 24 Graininess 24 Scratches and Pinholes 24 The Circle of Confusion 2.5 The Use of Selenium Toner to Increase Negative Contrast 25 The Pyro Negative 2.5

CHAPTER 4 CkEMiCAlS 27 The Reasonable and Prudent Use 28 The Material Safety Data Sheet 28 Health 28 Contact 28 Monochromatic Film Developing Agents (MSDS 2) 29 About Measurement Units 29 The Metric System 29 Purity of Chemicals and Water 30 Sizing of Paper 30 Solutions Used for Paper Coating, Developing, and Clearing 30 The Coating Solutions 30 Oxidizing Agents 30 Developers 31 Clearing Agents 31 Coating Solutions 31 Sensitizers (MSDS 2-3) 31 The Restrairiers (Oxidizers) (MSDS 3-4) 32 The Metal Salts (MSDS 2-3) 32 The Use of Metal Utensils 33 Developers (MSDS 1-2) 33 Formulas 33 The pH 34 Filtering of Deueloper 34 Temperature of Developer 34 Clearing Agents 34 Choosing a Clearing Agent 34 Etylene Diamiiie Tetraacetic Acid and the Sulfites (MSDS 1) 34 The Dilute Acids (MSDS 2-3) 3 5 Formulas 3.5 A Matter of Print pH 36 Bit ffering Sohtions 36 Toners 36 Negative Toning for Contrast 36 Print Toning 36 Sources of Chemicals 38 CHAPTER5 PAPER 39 Platinotype Papers 40 Practical Matters 41 ... viii CONTENTS

Some Characteristics Required of a PlatinudPalladium Paper 41 A Word About Paper Weight Measurements 42 Selected Platinotype Papers and Their Characteristics 42 Testing Techniques 42 Notes on Suitable Papers for the PlatinumPalladium Process 44 Papers for Single Coating 44 Acidification 47 Papers Ainenable to Acidification 47 Papers for Double Coating 48

CHAPTER6 Tkt FiRST PRiNT 49 The Sun Print 50 The Basics 50 Chemicals 50 Paper 50 Utensils 50 Negative so Procedure 50 Assessment of the Print 52 CHAPTER7 CkoosE YOUR Mdod 53 Methods of Contrast Control 54 The Ratio Method 54 Sodium Chloroplatinate (Na2) 56 Combining the Ratio and Na2 Methods 58 The Dichromate Method: Contrast Control Ingredient in the Developer 60 Standard Negative Contrast Ranges: The Dichromate Method 61 A Standard 61

CHAPTER8 CAli bRATiON 63 Calibrating the Light Source 64 Choosing a Pririt-to-Light Distance with a Point Light Source 64 Choosing a Print-to-Light Distance with a Fluorescent Tube Bank 64 The Step Tablet 64 The Visual Comparison Densitonieter 66 Methods of Contrast Control 66 Supplies 66 Notes on the Making of Test Strips 67 Technique: Time/Distance 68 Technique: Contrast Control 68 Palladium Printing with the Ratio Method 72 Standard Negative Contrast Ranges 73 Calibrating with the Dichromate Method 73

CHAPTER9 Tkt PlATiNUM ANd PA11AdiuM PRiNT 75 Utensils 76 The Test Strip 76 Coating the Test Strip 76 Materials Used for Developing and Clearing the Test Strip 78 Developing and Clearing 78 The Final Print 78 The Coating Instruments 78 Brushes 79 Coating Rods 82 CONTENTS9 ix

The Brush Versus the Coating Rod 83 Making the Final Print 83 Coating 83 Drying 84 Exposure 85 Dodging and Burning 85 Developing aiid Clearing 85 Dry Down 87 Using the Combined Step Tablet and Print to Adjust Printing Time and Contrast 87 The Visual Comparison Densitonzeter 87 Both Shadows aitd Highlights Are Too Dark 88 Both Shadows and Highlights Are Too Light 89 Shadotus Are Good, Highlights Are Too Dark 89 Shadows Are Good, Highlights Are Too Light 89 Shadows Are Too Dark, Highlights Are Good 90 Shadows Are 7-00 Light, Highlights Are Good 90 More Combinations 90

CHAPTER10 AdvANcEd TECkNiQuE 91 Masking of Negatives 92 Materials 92 Process 92 Working Light 92 Relative Humidity in the Laboratory 92 The Effects of High Paper Humidity 93 Prevention of Solarization 93 The Elusive Dinax 93 Observations 94 Hydrogen Peroxide 95 Brushes 95 The Use of Sizing Medium in the Sensitizer 95 Image Hue 95 Sizing 95 Developer and Tenzperature Controls 95 Metal loiis in the Developer 96 Combinations of Platinum and Palladium 96 Toning 96 Glycerin 97 Materials 97 Double Coating 97 Drying of the Coating 97 Materials 98 Method 98 Preparation of the Final Print 99 Drying 99 Principles of Etching and Spotting Platini~nzlPalludiiclnPrints 99 Materials 99 The “Black Plague” Cure 100 Presentation 101 Lighting 201 Matting 2 01 Framing 201 x CONTENTS

Numbering of Editions 101 Handling and Storage of Negatives 103

CHAPTER11 PRobkMs 105 Chalky or Anemic Prints 106 Uneven Coating 106 Graininess 107 Black Spots on the Print (The "Black Plague") 107 Streaking Blacks 107 Fog Versus Stain 107 Solarization with Palladium 108

PARTTwo SENSilOMETRY FOR ThE PlATiNUM/PA"AdiUM PROCESS 109

CHAPTER12 ThE FilM ANd PAPERCURVES 111 Silver and Platinunflalladium Curves Compared 112 The Individual Silver Curve 112 The Negative for Silver Paper 113 Steepness of the Curve 114 The Individual PlatinumlPalladium Curve 114 The Negative for a PlatinumlPalladium Print 115 Contrast Control 115 A PlatinunzlPalladium Curve for a High-Contrast Negative 115 Effect of Fog 116 A PlatinumIPalladium Curve for a Low-Contrast Negative 116 When the Negative Has Inadequate Contrast 118 The Family of PlatinunzlPalladium Curves 118 The Palladium Print 118 The Families of Palladium Curves 118 The Characteristics of Palladium Curves 119 A Palladium Curve for a Normal-Contrast Negative 119 A Palladium Curve for a High-Contrast Negative 120 Let There Be Light 120 The Matcher PrograniR 121 Negative Development for the Long Toe 124

CHAPTER13 USiNq ThE PRiNT CURVES 127 Refining the Standards 128 Shadow Values 128 Factoring in the Effects of Contrast Control 129 Analyzing the Print Curve 129 A Guide to the Families of Curves 130 The Na2 Method 130 Graphic Illustrations of Speed Changes Produced by Contrast Mixtures 130 Using the Algorithm 134 Examples of Various Negative Density Values 135 The Normal Negative 135 The Speed Bar 135 The High- Contrast Negative 138 The Low-Contrast Negative 139 CONTENTS xi

Being Practical 141 The Speed Point and the Corrected Speed Point 141 Papers 141 The Interpretive Process 142 Palladium 142 Using Portions of the Paper Curve 142 Using Intermediate Tonal Values 142 To Use a Portion of the Curue 143

APPENDIXA TkE CkEMiSTRY 01 DEvE\opiNq, CONTRASTCONTROI, ANd CkARiNG PROCESSES 145 The Oxidation-Reduction Reaction 146 The Reduction of Metals in Photographic Print Making 146 Berkeley’s Formula 146 Oxidizers 147 Oxidation 147 Reduction 147 Palladium Printing with Sodium Chloroplatinate 147 Using Na2 in the Traditional PlatinumlPalladium Print 148 In Summary 148 Clearing 148

APPENDIXB TkE LARGENEGATiVE 149 The In-Camera Negative 150 Perfect, but Sterile 150 Darkroom Magic 150 The Clinical Print 150 The Interpretive Process 150 The Contemplative Image 151 The View Camera Tradition 151 “In this Best of All Possible Worlds”-Voltaire, 1759 151 A Need for Subtlety 151 The Report of the Death of the View Camera is an Exaggeration 152 The Camera-Exposed Negative 152 Camera Size 152 The Ultra-Large Format 152 Organization of Exposed Film 153 First Phase 154 Second Phase 154 Last Phase 154 Processing the Large Negative 154 Tray Processing 155 Drum Processing 156 BTZS Tubes 156 Film Ha nge rlO p en Tank 157 Daylight Plastic Tanks 157 APPENDIXc SOME Fih/DEvE[OpER COMbiNATiONS TO PRodUCE A P1ATiNUM/PA11AdiUM NEqATivE 159 Choosing a Film 160 400Tmax 160 Delta 100 160 Efke 100 160 FP4 plus 161 HP5 plus 161 xii CONTENTS

320 TXP 161 Bergger 200 BPF 161 Classic 400 162 Twelve Film/Developer Combinations 162 Effective Film/Developer Combinations for Selective Processing of Platinum and Palladium Negatives 162 Rotary or Tray Development 162 Data 163 TubelJOBO Development 163

APPENDIXD PyRO ANd PLATiNUM PRiNTiNq 173 The Sensitometric Effects of Pyro Stain: “Spectral Density” 174 Observations 174 Advantages of Pyro: “Stain Is Your Friend” 176 Disadvantages of Pyro: “Stain Is Your Enemy” 177 Densitometers for Reading Pyro Negatives 178 Film Response to Pyro 180 Pyro Formulas 182 Other Pyro Formidas 182 Pyro Processing Information and Tips 182 Alternative Processing Controls with Pyro 184 Conclusion 184

APPENDIX E CRAhiNq DiqiTAl NEqATivEs FOR CONTACT PRiNTiNq PlATiNUM ANd PAlIAdiuM 185 Glossary of Terms 186 The Digital Versus In-Camera Negative Controversy 187 Materials and Equipment List 188 Some Digital Basics 188 Pixels Versus Dots 188 Digital linage Tones 189 The Digital Image File 190 Digital linage File Capture 190 Digital linage File Preparation 190 Imagesetter Negatives 192 How lmagesetter Negatives Work 192 Inkjet Negatives 192 How Inkjet Negatives Work 192 Printer Settings for Inkjet Negatives 193 Calibration for Platinum and Palladium Printing with Digital Negatives 194 Contrast Mixture 195 Determining the Standard Printing or Exposure Time 195 The Digital Negative Density Range 195 The Tonal Palette 196 The Process Adjustment Curve 196 Making a Digital Negative and a Pt/Pd Print 199 Adjusting the Image File Based on the Tonal Palette 199 Creating the Imagesetter Negative 199 Creating the Inkjet Negative 200 Making the Print 200 Evaluating the Print 2 00 Chemistry or Curve: When to Use One or the Other 201 About Precision Digital Negatives for Alternative Photographic Processes 201 ... CONTENTS XIII

APPENDIX F UlTRAViOlET LiqkT SOURCES fOR PALLAdiUM ANd PlATiNUM PRiNTiNq 203 Ultraviolet Printing Lights 204 The Sun 2 04 Ballasted HID Lamps (Mercury Vapor and Metal Halide) 2 04 UV Fhiorescent Tde Bank 2 05 Building Your Own UV Printer 205 Tube Nomenclature 2 06 Plate-Burners, or Graphic Arts Printers 206 Testing of UV Light Sources 206 Test Conditions 206 General Remarks About Results 207 Conclusions 207 The Question of Sharpness 208 UV Blockers 208 Window Glass 208 Specialty Glasses 208

APPENDIXG E~EMENTSOf PlATiNUM PRiNTiNq 21 1 The Negative 212 Duplicating 212 Materials 213 Paper 213 PlatinundPalladium Solution 213 Contrast Control 224 Technique 214 Sizing 214 Humidify ing 215 Coating 215 Exposing 216 Developing and Clearing 216 Finishing 217 Spotting Out 217 Filling In 217 Etching 217 Flattening 217 Waxing 217 SOURCES 21 9 BIBLIOGRAPHY 223 INDEX 227 xiv The First Edition of Platinum & Palladium Printing As with the acidification of paper, platinum printers, was published in 2000. It summarized and presented including Keith Schreiber, exchanged information techniques, most of which had been practiced for the among themselves and on the internet. For the first entire 130 year history of the platinum process. Now, time, platinum printers could increase paper contrast just four years later, I decided that a Second Edition was to accommodate less contrasty negatives without the due. In that relatively short time, advances occurred in destructive side effect of paper flocculation associated three specific fields, which have had an unprecedented with the more traditional oxidizers. Moreover, the impact on this medium. platinum could be eliminated entirely in favor of the less costly and supremely elegant palladium.

THE ACIDIFICATIONOF PAPER THE DIGITALNEGATIVE As chronicled in this text, 1985 was not a good year for platinum printers. Without prior warning and working For the short time that digital techniques have in a secretive fashion, the majority of paper makers been available to the photographer, the influence has used carbonates and other additives to change their been enormous. papers from an acidic to an alkaline pH. This was The tools for the making of digital images are now done to conform with the “acid free” recommendations easily acquired, and the equipment is inexpensive. It of preservationists. The chemical makeup of the acidic has, however, generated a divide between commercial platinum and palladium coating agents cannot be spread and “fine art” photography. Today’s commercial on to an alkaline surface. A typical acid-base reaction photographer cannot survive without digital capabil- occurs resulting in precipitation of unwanted salts. ities. However, while some digital manipulations have Many fine papers, such as Rives BFK, Arches, entered the art scene, historic processes have more or Fabriano Artistico, Uno, and other thick watercolor less remained a hands-on endeavor. That is, with the papers could no longer be used for platinum and exception of the digitally enlarged negative. palladium printing. Here, there is a cause for concern. In some hands Shortly after the publication of the First Edition the simple process of exposing a generic PtPd coating to of this text, platinum printers began to experiment UV light could just be the final step of realizing an image with methods to acidify the alkaline coating of some conceived on the computer monitor. papers. Dilute oxalic acid was found to be the best With that in mind, Mark Nelson has designed agent, usually a 1% or 2% solution. The paper either a program that uses digital imaging not as a substitute was coated by or soaked in this solution. When this for time-honored photographic techniques, but as an technique was described on the internet, papers of adjunct to image making, allowing all the printing all types immediately became suitable for platinum and controls outlined in this text. This is presented in palladium printing. As a result, Chapter 5: Paper, Appendix E: Crafting Digital Negatives for Contact was re-written to introduce and classify papers which Printing Platinum and Palladium. had been excluded from the First Edition.

THE REVISIONOF PLATINUM SODIUM CHLOROPLATINATE( NA~) & PALLADIUMPRINTING

I consider sodium chloroplatinate to be the most The early chapters: Setting Up a Laboratory, The startling “rediscovery” in the 25 years that I have been Negative, and Chemicals, were revised only to the engaged in platinum printing: more important, in extend of adding new equipment and introducing many ways, than the “digital revolution.” While sodium chloroplatinate (Na2) to the list of chemicals. perusing historic literature, Richard Sullivan came The chemical reactions involving Na2 were added to across the mention of sodium hexachloroplatinate IV Appendix A: The Chemistry of Developing, Contrast as a possible oxidizer for use as a contrast control agent. Control, and Clearing Processes. This was accomplished (This compound, when used in the coating material for under the guidance of chemist Howard F. Efner, who platinum and palladium printing, has entirely different did the initial studies on chloroplatinate. properties than potassium chloroplatinite, the source Chapter 5: Paper, was completely rewritten to include of the elemental platinum which defines the image.) acidification techniques and re-introduction of many xvi PREFACE TO THE SECOND EDITION AND ACKNOWLEDGMENTS

fine alkaline papers that now can be used with the PtPd be replaced by digital technology. In fact, it may very process. The introduction of Na2 to the chapters on the well be that the “hands on” alternative photographic making of the Pt/Pd print presented a challenge. The processes, such as platinum and palladium printing Ratio (A+B) method of contrast control presented in may be most instrumental in preserving many of the the First Edition is still the method of choice for traditions of fine photography. For those committed many Pt/Pd printers and will remain so in the future. to digital imaging, there are far more exciting avenues, I, therefore, had to present the Ratio and Na2 contrast such as the motion picture and holography where the control methods in a parallel fashion, not unlike writing fruits of technical innovation can be applied. about computer software for two different operating Unfortunately, some film manufacturers have not systems. shared my views and have jumped on to the digital I facilitated this by adding a new chapter in the bandwagon. As a result, some very good films have center of the text, Chapter 7: Choose Your Method. either been discontinued in certain sizes or made Here the two methods of contrast control, as well as available on outrageously priced minimum orders. the Dichromate method are presented in detail. Chapter 8, In response, I have tested many films which can Calibration and Chapter 9: The Platinum and Palladium be substituted for those recently made unavailable. Print, were rewritten to accommodate the Na2 method. Appendix C: Some Film/Developer Combinations to For Chapter 10: Advanced Technique, and Chapter Produce a Platinum/Palladium Negative, lists 12 film/ 11: Problems, I am indebted to my many former students developer combinations, emphasizing films from com- and colleagues for material. Stan Klemik and I compared panies still dedicated to meeting the requirements of notes and incorporated many new concepts into these view camera photography. chapters. He also authored Appendix G: Elements of Knowing that “cutting edge” technology is readily Platinum Printing, presenting his unique way of printing available on the web, I eliminated some of the subjects on humidified paper. As a supplement to this, I conducted from the appendices in the First Edition. Instead some studies on the effects of humidity, which are I included subjects based on solid investigative work summarized in Chapter 10. and of value to the Pt/Pd printer. In Appendix D: Pyro Part 2: Sensitometry for the PlatinudPalladiuin and Platinum Printing, Bob Herbst, using a UV trans- Process, was condensed from three chapters to two. mission densitometer, shares his results in quantifying During the four intervening years between editions, the characteristics of a pyro negative in regards to PdPd I covered this topic with many workshop students. printing. I hope that from learning from them I made this In Appendix F: Ultraviolet Light Sources for difficult subject easier to grasp. Chapter 13: Using the Palladium and Platinum Printing, Sandy King has Print Curves, was supplemented with new graphics and written a complete summary of the effects of various the introduction of the Speed Bar, a slide rule device that UV light sources on the reduction of platinum and makes the calculation of printing times less demanding. palladium salts. I have included Let There be Light, which I first presented at the APIS meeting in 2003. Here, a way of “previsualization” is presented to capitalize on the ACKNOWLEDGEMENTS exception qualities of the pure palladium print. Appendix B: The Large Negative, and C: Some Film/ There is little information in this text that was not Developer Combinations to Produce a Platinum/ gleaned from the work of others. I simply subjected Palladium Negative, were revised to reflect the current the information to investigative testing and codified it controversies regarding enlarged digital negatives in in what I hope is a logical manner. A special amount respect to the traditional in camera view camera of gratitude is due to those previously mentioned, as negative. In Appendix B, for the first time in the writing well as the proof readers par excellence: Stanley Swarts, about Pt/Pd printing, I interjected my personal opinions Professor Emeritus of Geography and Ernest Fokes, on the subject. MD retired, who reviewed the chapters on sensitometry. The platinum printing process and the view camera As I recently told Ernest: “When a brain surgeon doesn’t have existed side by side for almost the entire period understand what I have written, I had better redo it.” after the invention of photography and have largely defined a way of seeing. It is not likely that either will - Dick Arentz 2004 xvii xviii PREFACE AND ACKNOWLEDGMENTS

This is a book is about the craft and science of platinum cover the distinctions between the two, as well as and palladium printing. For the most part, creativity discussing the equipment that is unique to this form of or “Art” cannot be taught in a text or in the photographic printmaking. I wish to thank dermatolo- classroom-it must come from within. The teacher can gist Fred McElveen, M.D., for providing me with the only plant the seed and, if there is any growth, nurture practical understanding of the properties of ultraviolet it a bit. My goal, therefore, is simply to provide light I have presented. some of the tools needed for the artist to express and The making of the photographic negative is an communicate his or her vision to others. essential part of the platinudpalladium process and My first tasks in planning this text were the matters is covered in detail. The subject of the pyrogallol nega- of inclusion and exclusion. Although I easily could have tive is one of the more elusive topics in photography. included more than I have, a seemingly endless recita- Although we were not able to reach any dramatic tion of photographic technology would have defeated conclusions, I am indebted to Bob Herbst, Grant Evens, the purpose of a practical guide for the platinum and and Eric Marler for their help in this area. palladium printer. Nevertheless, to exclude vital infor- Of all the sciences involved with photography and mation out of the fear that some might be scared photographic printmaking, chemistry is most funda- away by “science” would be a disservice to all who wish mental. For the optimum practice of this medium, the to master this unique process. basic chemical reactions involved should be understood. Here, I was guided by my contact with hundreds While I had at one time taken some advanced college of workshop students. Their backgrounds varied from chemistry, much had faded away with time. Drs. John health science professionals and individuals with a P. Schaefer and Richard Foust patiently disassembled Ph.D., to art students with only a minimum of high my original chapters and offered the necessary sugges- school science. In response to their questions and needs, tions for me to attain a reasonable degree of accuracy. the first Outline for Platinum and Palladium Printing One of the more pleasant experiences of writing this was written over ten years ago. It is from that Outline book came when my daughter, Pamela Motley, a that this text is constructed. Some presentation of graduate student in chemistry, invited her old man to elementary physics, mathematics, and chemistry is her office and brought him up to speed-at the college essential. It was necessary to find a middle ground- freshman level-on the redox reaction. not too complicated, yet not too simplistic. Fortunately, Recently, the deleterious effects of many chemical those who are attracted to platinum printing possess substances have come to be more appreciated. The the innate intelligence and curiosity to grasp the careless practices of the past are no longer tolerated. fundamental concepts quickly. Unfortunately, with this surge of new information and I also benefited in writing this book from my regulations, those who have applied indiscriminate students. Because of the varied backgrounds represented interpretation of data to many essentially safe photo- by workshop participants, I gained as much or more graphic processes have victimized platinudpalladium than I imparted. Without their input, I would not have (PtPd) printmaking. I have made the effort to find had the temerity to attempt a project of this nature. a logical middle ground by describing the Reasonable Most importantly, I have made the effort to connect and Prudent Use of chemicals. Safe alternatives have scientific subject matter and technique to the ultimate been offered in place of the few truly harmful agents purpose of platinum and palladium printmaking. used in the Pt/Pd process. One, formaldehyde, has Consequently, images made using the concepts pre- been eliminated in James Hajicek’s formula for gelatin sented here are reproduced throughout this text. paper-sizing. Platinum and Palladium Printing is divided into two But perhaps the greatest effort was made in parts. Part One: The Process, provides the theory untangling the frustrating problem of finding papers and practical applications indispensable to the platinum appropriate to this process. I am indebted to Kathryn and palladium printer. Part Two: Sensitometry for the Clark of Twinrocker, a paper company in Indiana, Platinum/Palladium Process, presents the actions of light for her generosity in assisting me in understanding the on platinum and palladium materials. basics of papermaking in 1988-and allowing me to For my discussions of platinum and palladium in spend two days making feeble efforts at dipping the Part One, I chose to make comparisons to the more ubi- moulde into the vat of pulp to make paper. quitous silver gelatin process. The platinudpalladium Keith Schreiber, formerly at The Center for Creative (Pt/Pd) laboratory is different from the traditional Photography in Tucson, was one of my workshop photo darkroom, and I have made some effort to students in 1991. Years later, unbeknownst to me, he had quietly assembled a comprehensive series of paper tests consultation of recommended texts. Even if some of that now serve as the basis for Chapter 5: Paper, which these practices are not completely adopted, reading he also coauthored. Many of his exceptional palladium the section will give the reader a better understanding prints are reproduced in this text. We have presented of the process. a list of papers that many will find helpful. We have As other helpful information is available, but not continued our dialogue with paper companies with the necessarily essential to the development of the text, hope that some of the mysteries of papermaking may I have included an extensive set of appendices. Most become decoded. significantly, the making of a large negative is described, Chapters 6 through 8 delve into the process of either made directly in camera or though photomecha- platinudpalladium printing from the simple sun print, nical means. As a large camera user, I have had limited to calibration of equipment and the making of the final experience in negative enlargement. Rod Klukas, Richard print. Here I present the many practices that I have Lohmann, Kevin Martini-Fuller, and Norma Smith accumulated over a twenty-five-year career. Two meth- shared their knowledge of the photomechanical pro- ods are discussed in detail: the traditional “A + B” cesses. Since I am also somewhat of a computer illiterate, method, which utilizes the contrast control ingredient I am grateful to John Schaefer and Dan Burkholder in the paper coating, and the dichromate method of for providing their input on the subject of negative controlling contrast by developer. Two of the fine computerization. As many comprehensive guides to the ammonium-based processes, the MaldeKUare process computerized negative exist in book form, and on the and the Ziatype are introduced in Appendix D: The Internet, a complete guide here would be redundant. Ammonium-Based Process. Instead, I provide an introduction with source material. In presenting methods for making a Pt/Pd print, I wish to thank Phil Davis, Darkroom Innovations, some degree of editorial selection was necessary. Today, and Kieth Schreiber for sharing the Plotter Program’ files hundreds of fine photographers have described dozens used to compile the film/developer combinations listed of methods of making platinum and palladium prints. in Appendix B: Some FildDeveloper Combinations to Since it would be impossible to cover even a small Produce a Platinum/Palladium Negative. segment of this information, the reader is encouraged While compiling the basics of the ammonium-base to “surf the net” for discussion groups and Web sites. processes, I was in constant E-mail contact with In Part Two: Sensitometry for the Platinum/ Professor Mike Ware of Buxton, England. Due to his Palladium Process, the actions of light on platinum generosity, we have presented an outline of the Malde/ and palladium materials are presented for practical Ware process. And during the summer of 1998, Richard application with the inclusion of various exercises. Sullivan and Carl Weese supervised me in making my I introduced sensitometers in Part One, but they were first Ziatype. not required for the making of a Pt/Pd print. In Part Kevin Martini-Fuller and Alan Spiegler read and Two, the transmission densitometer is presented as an provided corrections for the manuscript. In addition to essential tool in the making of predictable and duplic- sharing their expertise, Alan Spiegler and Keith Schreiber able platinum and palladium prints. For some, this used their other talents to make the transparencies used may be a quantum leap, for it requires some effort and for all the photo illustrations and plates. xx lNTROdUCTiON XXi

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Today, in the field of monochromatic photography, developed in a solution of naturally occurring organic platinum printing has been categorized as one of the salts and cleared in dilute acid or sulfite compounds. alternate processes. With a myriad of other photo- Minimal washing is required. The print is allowed to dry graphic printing methods available today, the appli- on a screen. cation of other nonsilver metals, inks, pigments, and The finished hand-coated print consists of pure dyes with a bas-relief matrix are now considered an platinum and/or palladium metal imbedded upon and alternative to the silver gelatin print. inside the paper at a considerably greater thickness than It was not always so. In the nineteenth century, can be laid on the surface by machine. A well-made although Fox Talbot’s first photographs were based platinum or palladium print excels in the delicacy of the on the reactions of silver chemicals to light, printing tonal scale, image color, and depth. Papers of different procedures utilizing different materials and techniques texture, hue, and weight can be used, so interpretation is soon became available. Within a generation, silver not limited to the dictates of a uniformly manufactured was frequently considered a second choice to the more product. elegant examples of carbon, gum bichromate, bromoil, Depending on the market costs of precious metals, photogravure, Woodburytype, and platinum. palladium is more often less expensive than platinum. At that time, all processes required a large negative Contemporary workers frequently combine platinum for contact printing. By the early twentieth century, and palladium metals (Pt/Pd), or print with pure pallad- however, with the development of faster film for the ium. With a mixture of both metals, the characteristics hand-held camera and enlarging paper-both of which of a pure platinum print can be essentially duplicated at rely on silver emulsions-the silver gelatin print became less cost. Depending on available techniques, the print the predominant printing process in monochromatic color of a platinudpalladium print can range from photography, a position it still occupies today. neutral gray to sepia. The midtones, rather than being Nevertheless, the nonsilver photographic processes compressed as with modern silver paper, are evenly have endured and have recently undergone a resurgence. distributed, allowing for great subtlety in print values. Some are practiced out of academic interest. A few, Pure palladium particularly captures the nuances including platinum, have resumed their place among the of the mid- to high-tones. It is frequently possible to finest of artistic media. print brilliant highlights directly while still maintaining Platinum, as did other early processes, originally texture. required hand preparation of the paper. Then, by the As one of the most permanent of photographic turn of the century, platinum and its sister metal processes, platinum is also one of the most environmen- palladium were available in many commercially pre- tally safe. The chemicals used are relatively inert metals, pared forms, only to disappear during the next twenty common cations (sodium and potassium), iron oxalates years as styles and techniques changed and the minia- (rust), and weak acids. The oxidizing compounds, ture camera gained popularity. Today platinum printers while hazardous, are used in infinitesimal quantities. practice it as it was originally described in 1872-a For some compounds described in the literature that are hands-on printmaking process. now found to be hazardous, satisfactory alternatives A platinum worker must still contact print with exist. standard commercial silver-based film; if enlarging is In choosing platinum, the drawbacks must also be desired, it must be done through internegatives or with considered. It is a process made cumbersome by camera the aid of computerization. The film is processed for size or negative enlargement. Platinum and palladium greater contrast than is suitable for modern silver gelatin. salts are expensive. Technical control is necessary to Working in low incandescent light, a platinum and/or minimize waste. Despite attempts to capitalize on the palladium salt mixed with a sensitizing ingredient is novelty or “preciousness” of platinum, some imagery brushed on to a compatible, well-sized paper. Contrast does not do well in platinum or palladium. Simply put, control equivalent to a dozen silver paper grades is platinum does not make bad photography acceptable. achieved through the use of minute amounts of oxidizers. Perhaps these latter characteristics should be con- After drying the paper in heated air, a negative is sand- sidered the greatest advantage of platinum and other wiched between glass and the dried, coated paper. alternate processes. In a way, to do them well, one must Approximately five minutes of intense ultraviolet return to the inquisitiveness and noncommercial incen- light, either directly from the sun or a specific light tives of the nineteenth-century amateur photographer source, is passed through the negative to the sensitized and inaster a craft for the purposes of personal platinum and/or palladium salt. The print is then satisfaction and achievement. Platinum printing is one xxii INTRODUCTION of the easiest of the nonsilver processes to learn. The The step-by-step format is meant to guide the platinudpalladium process also offers a number of platinum or palladium printer through the multiple variations, which the photographer can closely control. sensitometric, chemical, and mechanical tasks that The advantage, however, makes the process a bit like must be mastered for consistent and predictable chess: it is easy to learn the basic moves, but because results. If, in the near future, the pages are dog- of the options available to the skillful player, the eared and liberally marked with notations and complexity increases as the subject is mastered. various chemical stains, then it will have served its This book is flexibly bound with the intent that purpose well. it be used as a laboratory manual rather than a library Communication with the author can be done by text. e-mail at [email protected] or www.dickarentz.com.

Thispageintentionallyleftblank CHAPTER 1

PLATINUMAYD PALL-ADIIJM

PLATE 1 .I Lt\tNS, ENC,(~N~LOOO I L X 20 INtk Pd

3 4 THE PROCESS

PLATINUMPRINTING IN THE TWENTIETHCENTURY practiced by hundreds of photographers, covering the spectrum from the amateur to the significant photog- The first patent for the platinum process was obtained raphers of our time. by William Willis in 1873. Improvements and modifica- tions followed during the remainder of the nineteenth century (Pizzighelli and Hubl, 1886; Abney, 1895; THE PLATINUM/PALLADIUMAND SILVER Nadeau, 1994; Sullivan and Weese, 1998). PROCESSESCOMPARED By 1900, dozens of commercially made platinum and palladium (Pt/Pd) papers were available in England and the United States. However, within two decades, as the result of two unrelated occurrences, platinum print- ing was brought to the verge of extinction. First of all, World War I started in 1914. The need for platinum in the manufacture of munitions (it was used as a hardener for the tips of cannon shells) caused the market price of the element to reach astronomic highs during that time. Manufacturers discontinued the papers. Secondly, recent developments in photography allowed for an increase in the speed of lenses and film. Similar increases in the printing speed of silver paper led to the design of a practical enlarger. Smaller, hand-held cameras could be used; the photographer could later enlarge the image to any size desired. Platinum, as with most of the nonsilver processes, did not have the light sensitivity to react to the relatively dim light of the enlarger. Many elegant nineteenth-century processes, as well as the traditional tripod-mounted camera, fell into disuse. By 1920, no commercially made platinum papers were available in the United States. Some photogra- phers, such as Laura Gilpin, imported their paper directly from England. In the mid-1960s a resurgence in platinum printing began. Because no commercially prepared papers had been available since 1941, photographers went to the literature to repeat the processes described by Willis, Pizzighelli, and others. By 1970, Irving Penn and George Tice were making hand-coated platinum and palladium prints. With the explosion of university photography programs at the time came a renewed academic interest in all nonsilver processes. Also, with photographic education, a new, sophisticated audience for fine art photographs was born. Galleries dedicated to the sale of photographs to connoisseurs and collectors opened throughout the country. Custom printers discovered that established photographers in the fields of fashion, PLATE 1 .3 CL~RFSS.POINT Lobes, CA~IfORNl4 1977 5 X 7 lNtk advertising, portraiture, and photojournalism wanted PT/Pd TIit 10Nf5 01 TIIF PRINT dA\E brfk MORI ibEhl\ dlslRlbtIrFd BF(~LSF01 Ih[ pROVOLNCtd \blllf) TO 5EpARATE klc,li \4[IltS. IkF their images rendered in platinum and palladium. bAtkllGkTlN6 15 NOU MORt AS5IMII3TEd INTO rkr IMACiE For a brief period following this major entry of photography into the art markets, platinum, along with Most significantly, silver gelatin paper is a manufac- other recently reintroduced processes, was judged more tured item. Minute particles of silver are imbedded in a by its status as a novelty than by its content. Today, microscopic layer of gelatin. The glossy or semigloss platinum printing has found its proper place. It is silver print is capable of reflective densities greater than any matte-finish, hand-coated process. Also, the amount printing. A contact print is required. Unless the of detail or “sharpness” in the print is enhanced by the negative is reprocessed to a larger size, the size of the slick, thin surface of the paper. platinum or palladium print is determined by the Pt/Pd printing, when practiced as a hand-coated format of the camera. procedure, has a surface of metal granules many times 3. The maximum reflection density (depth of black) is thicker than any mechanically made paper. As such, it much greater with silver than with platinum. takes on many of the characteristics of the hands-on 4. Optical detail or “sharpness” is greater on printmaking processes. commercially prepared silver paper than what is Considering the many unique properties of each usually found in any hand-coated process. process, the platinum or palladium print is no more 5. Because of the myriad of commercial materials superior to a silver print than the cello is to the violin; specifically made for the silver gelatin process and it simply has characteristics that make it different. With the use of the enlarger to compose and expose, silver certain imagery, the platinum or palladium print offers printing is generally easier to learn and practice than a refreshing, complimentary change from the traditional the Pt/Pd process. monochromic silver print. To carry the analogy a step 6. Silver is capable of producing a black, cool, or further, some music will be amenable for transposition bluish black not possible with traditional platinum from one instrument to the other, and some may not. images. (For an exception, see the Ziatype at Similarly, in imagery, some images can succeed in either http://www.bostick-sidlivan.com) media; most will work in only one. Compared with commercial silver papers, the Pt/Pd As you can see, neither process is superior. For the process has the following attributes: beginning photographer in particular, I believe that many nonsilver processes should be explored in addition 1. It is one of the most stable of the photographic to platinum. If a decision is made to concentrate on a processes-as stable as the paper it is printed on. process other than silver, taking into account the added 2. It has a delicate response to highlights. difficulty and expense, it should be made based on 3. The midtones of the print are more evenly dis- factors other than the desire to be different. In many tributed, creating a distinctive “platinum” image. ways, silver is still the most versatile and effective 4. The process of hand coating allows the printer to medium for photographic expression. increase the depth of metal particles, resulting in an image with extreme physical presence. 5. There is a wider exposure range of paper contrast, PLATINUMAND PALLADIUMCOMPARED allowing the use of a rich, “contrasty” negative. 6. There is considerable choice of papers, allowing for For many years, my “platinum” prints have actually variations in image tone, paper hue, and texture. As been equal parts each of platinum and palladium. My a hand-coated process, platinum or palladium can tests have shown little discernible difference between also be placed on materials other than traditional a platinum and a Pt/Pd print. (See the section “Image artists’ paper. Color” in Chapter 10: Advanced Technique.) The pure platinum print is cooler and more ame- Despite some deterioration in manufacturing tech- nable to certain toning techniques; however, the tone niques, silver gelatin paper has a distinct set of advan- of a print made from both metals can be controlled by tages that have made it the most popular of the the choice of developer. The cost advantage of this monochromic printing processes. Compared with plati- technique is usually significant. In fact, most “platinum” num, silver exhibits the following characteristics: prints made today are actually a combination of platinum and palladium.’ 1. It is less expensive than platinum or palladium. (A typical small silver print can be made for about $1.00, while Pt/Pd print of equal size will cost at least $5.00 in materials.) ’. This preference map change with the introduction of sodium 2. A silver print can be made from an enlarger, using chloroplatinate (Na2)as a contrast control agent. As will be discussed throughout this text, by using Na2 as part of the coating solution, a much smaller negative. The printing speed of many of the disadvantages associated with a pure palladium print have platinum or palladium is much slower; conse- been overcome. I predict that soon the use of pliitinum as part of the quently, a projected image cannot be used for PtlPd print will decline. 6 THE PROCESS

Platinum and palladium are both relatively inert 4. More susceptible to bleaching in the clearing noble metals of great similarity. With minor variations, process, unless care is taken the mixing, coating, and developing are identical. The 5. Characterized by a greater latitude (a more prints produced by each of the metals are similar but contrasty negative is needed) have some individual differences. 6. Deeper blacks and a higher Dmax can be obtained When compared to Pt/Pd, palladium is: compared to those of platinum alone or a PdPd mixture 1. Usually less expensive (approximately one-half 7. With a given paper and contrast range, the the cost) palladium print often exhibits smoother tones. 2. Warmer (more sepia) in tone 3. More easily solarized. This is true solarization, as Printing with pure palladium may be precarious, but compared to the Sabattier effect. (See Solarization in it is often worth the effort. If well done, it is the most Chapter 11: Problems.) exquisite of printing processes.

PLATE 1.4 MORETONFic, TRFF, HLIVAIEI.Hi\\uii I Y90 7 x I7 inch P1iPd CHAPTER 2

PLATE 2.1 "~i~~rht~,~,'WYC)MIN(, 2000 I2 x LO Pd

7 8 THE PROCESS

It is best that a separate, well-ventilated space be planned The coating area should be far enough away from for any photographic process, including platinum print- the sinks to avoid any contact with water splashes ing. For designing a laboratory, the following guide is (Figure 2.1). Any water droplets on the paper before or recommended: Kodak: Building a Home Darkroom after coating will permanently ruin the print. If a coating (Publication KW-14, 1986). Calumet Photo, Inc. has rod is to be used, a perfectly flat piece of tempered plate extensive choices for sinks, plumbing, filters, tempera- glass must be provided as a coating surface. ture-control units, and exhaust systems. (Source: CPI)’ A flat sink large enough to take at least five trays When designing modifications to a typical photo- and a washing tank is necessary (Figure 2.2). An addi- graphic laboratory for the purpose of platinum and tional laundry tub is valuable for mixing solutions.2 palladium (Pt/Pd) printing, the decision must be made as to whether silver or color printing is contemplated for the present or future. If not, considerable changes in the design normally recommended for a darkroom may be incorporated. Most significantly, unless photomechanical enlarge- ment of negatives is planned, safelights or an enlarger are not needed. Because the actual exposure is best done in another space, the “wet” area of the laboratory can be mostly occupied by the working sink, designed to accommodate the largest negatives and prints you think you might make. (Plan ahead; do not be disappointed when your sink will not take the 12 x 20 trays.) An adequate flat surface for coating the platinum and/or palladium solutions onto the paper should also be set aside in this room.

THE WET SPACE AND COATINGAREA

Although the platinudpalladium process can be done in low incandescent light, negative development requires a light-tight environment. If using tubes or a JOBO’K processor, a space need only be provided for the loading of tubes and film holders. (See Appendix B, “The Large Negative.”) The wet space and coating area are ideally situated in the same room. Both coating and processing are done under the same low incandescent light source. Because a humidity of 40 to 60% is recommended for coating, in most climates, the wet area of the laboratory can maintain more consistent humidity than most other rooms. A hygrometer is recommended. A good one is the Airguide 112, which sells for about $70. (Source: VWR) In extreme climatic situations, a humidifier or dehumidifier may be needed. The solutions used for FIGURE 2.2 Tlir Wrr SPACE. the coating and storage area for paper should both be located at room temperatures of 65 to 70’ F. , -. For mixing from powder, a stir-and-heat plate is highly reconi- mended (Figure 2.3). Potassium oxalate developer works best at 90- F. ’. From this point forward, sources of materials will be referred to by The heated plate can maintain that temperature. Most importantly, designated abbreviations, which can be found in the Sources section of however. the magnetic stirring function allows you to be distanced the text. from the powder and fumes during mixing. (Source: TS) light-blocking drapery can be constructed. Then, if the exposure unit is on a timer, additional prints can be coated while another is “cooking” under the light source. This drying and exposure room is the best place for handling negatives. A light table and densitometer can be situated here, as well as a vault for storage of negatives. Fiberglass drying screens and a retouching table can also be located in this room (Figures 2.4 and 2.5).

I use both sides of the film holder for identical exposure of each image. To supply “insurance” in

Two light sources are recommended: a set of 40-watt bulbs at least 4 feet from the coating area and devel- oping trays, and a standard fixture with adequate wattage to view prints after development. Because most of your time in the darkroom will be spent standing, purchase antifatigue rubber mats.

THE DRYINGAND EXPOSUREAREA

Ideally, the working areas should consist of two separate rooms. Practically, many do not have the available space or means to construct such a facility. A compromise can FIGURE 2.4 Tkt Llclkr TAblF be achieved by dividing the laboratory into two distinct areas, by utilizing a room divider, for example. The following recommendations are based on “ideal” circumstances. Drying is usually done with a hair dryer. Because particles of the coating may conceivably be blown into the air, a larger, more open space is recommended. Also, continuous use of a hair dryer in a confined space will alter temperature and humidity. For smaller prints, if budget and space allow, a drying cabinet is a preferable alternative. A specific paper dryer for platinum and palladium prints is available from Edwards Engineering. (Source: EE) Also, see Chapter 10: Advanced Technique for a description of the drying apparatus. The light source, unless well shielded, will emit ultra- violet (UV) rays beyond the print to be exposed (usually 3-15 minutes). Freshly coated paper or chemicals used for coating are best protected from UV light. Anti- actinic glasses should be worn for eye protection, and children should be kept away. (Source: PS) A curtain of FIGURE 2.5 Tlit DRLINC~SCREEILS 10 THE PROCESS

case of a scratch, light leak, or blunder in develop- For the ultra-large camera worker, 3-inch Purdy ing, I produce an extra set of negatives. The original natural bristle brushes set is stored in a fire-retardant cabinet. The extra set For coating in humidity, a Richeson brush is kept in another building. Clean blotters 112 any lab, provide for escape in the everit of fire. If there are no windows, consider putting one in, covering it with thin Masonite, and keeping a tool PHARMACY accessible for rapid removal. If the space is later sold, the presence of a window will increase the value to a One-ounce dropper bottles (at least 4) nonphotographer. For spaces in a windowless area One-ounce plastic medicine cups away from the main living area, check with the fire Cotton applicators department for remote access to smoke alarms. Hypodermic syringes for rod coating. (In some states, you may need a prescription from a doctor. Discard the needle after securing it in the plastic MATE RI ALS cover.)

Items needed for the lab are listed in the following CHEMICALSUPPLY HOUSE sections according to where they may be purchased. Chemical balance (optional) Stir-and-heat plate (optional) THE WET AREA Filter paper, student grade PHOTO SUPPLIER Glass funnel (for filtering metal salts) Hygrometer (Source: VWR) Clean towels pH 0-14 paper strips (Sources: VWR, Ll, TS) Clock timer Five ml measuring graduates (3) Hot plate (use wire-mesh insulator over coils if a SPECIALTYSUPPLIER glass container is used) Latex gloves, lightly lubricated with silicon Antistatic solution (Source: MD) Print tongs not previously used for other processes Coating rods Sponges One sheet of tempered double-thickness glass Stirring rods pH pen (Sowce: Ll) Trays not previously used for silver, at least one size Anti-actinic glasses (Source: Ski shop, PS) larger than print paper Two-liter stainless steel or Pyrex container for developer THE EXPOSUREAND FINISHINGAREA SPECIALIYSUPPLIER

THE COATINGAREA Printers' Rubylith" material (from printing shop) ART SUPPLY Step tablets (see Chapter 8: Calibration) (Sources: Dl, GAS, BS) Black felt-tip marking pen Drafting tape PHOTO SUPPLIER Plastic pushpins Scissors Air syringe or canned air Single-edged razor blades Cotton gloves

PHOTO SUPPLIER BEAU~YSUPPLIER

Camel hair negative-dusting brushes, 1- and Hair dryer (Buy a professional model. Diffuser is 2-inch sizes optional.) GENERALSUPPLY CONTACTPRINTING FRAMES

11 x 14 thick corrugated cardboard There are alternatives to using a contact printing frame. A vacuum easel is superior. If the light is coming from above, a heavy sheet of plate glass over foam rubber is ART SUPPLY quite adequate. If you use a contact printing frame, choose one of #OOO fine camel-hair brushes high quality. Most frames available from photo supply Light table houses are inadequate: The springs are not strong Watercolors in ivory, black, burnt umber (tubes) enough, and the inexpensive wood flakes off between and titanium white (powder) the negative and glass (on the sky in the photograph, Watercolor dish of course). The older ones are best. Check catalogues of 12 THE PROCESS

VK””Il3 uv

100 200 250 320 380 400

Nanometers

FIGURE 2.7 Tki U~TRAVIO~EISPEC IRIIM. SkOwN4 rIiF ACTINIC RAN~EAT Wklck PlATlNUM ANd PAllAdlllM SAlT5 ARE CONLERlEd

FIGURE 2.6 Tkf CONTACTPRINTING FRAME^ specifically designed for the UV spectrum3 is a better choice if there will be continuous contact. Further cov- used photo equipment. Otherwise, good sources exist ering of the light source is also advisable, particularly for new and better contact printing frames (Figure 2.6). if others will be in the vicinity. (Sources: BS, VCS) The following types of UV light sources are available. Most will need a printing frame or heavy glass to hold the negative and coated paper in register. THE ULTRAVIOLETLIGHT SOURCE Some of the more expensive commercial “plate burners” come with a vacuum easel. \()I! For a more complete discussion of UV light sources, see Appendix F: Ultraviolet Light Sources for THE SUN Platinum and Palladium Printing, by Sandy King. The sun was the first light source for all photographic The light needed to convert the sensitized salt used printing and remained so for most of the nineteenth in PdPd printing is in a rather narrow region of the UV century. Because sunlight contains all of the spectra, spectrum. Light from other spectra is inadequate or more portions of the sensitized salts darken to form a useless. Frequencies of light waves are measured in distinct “provisional” image. By using a hinged printing nanometers. A nanometer (nm) is one-billionth of a frame, one can-with practice-gauge the exposure meter. The UV spectrum is defined as the range of process by opening one side of the back, keeping the emissions from 200 to 400 nm, although wavelengths negative in register. A well-made platinum or palladium from 100 nm exist in a vacuum (Figure 2.7). UV light is print will require from 5 to 15 minutes of direct midday further divided into bands of UV-A (320 to 400 nm), sun (see Chapter 6: The First Print). UV-B (250 to 313 nm), and UV-C (200 to 250 nm). The Obviously, the amount and type of sunlight is actinic conversion of the iron salts used for platinum contingent on climate, atmospheric conditions, season, and palladium printing occurs most often in the UV-A and time of day. Although these variables are fascinat- and the upper ranges of the UV-B spectra. Fortunately, ing while learning the PtPd printing process, the health hazards of UV light are less at these higher eventually a more dependable source of light will be frequencies, whereas the nanometer range of UV-C and needed. the lower UV-B is highly destructive to the skin and is carcinogenic. Equally fortunate, most of it is filtered out by the atmosphere. For personal protection, the UV sources used in platinum printing are such that severe x Solar Specs”, designed specifically for protection from the UV measures need not be taken. Sunglasses used for skiing spectrum of light, are manufactured by Psoralight Corporation. They help to cut the annoying glare and filter some of the are available in clear (10811’C) and gray (1082PC).They sell for $8.50 UV spectrum. However, shielding the eyes with glasses each. (Source: PS) MERCURYVAPOR, METALHALIDE, AND UV FLUORESCENTLIGHTS This section discusses the materials available from various sources (see also Appendix F). In that section directions are included to build your own luminaire or UV fluorescent tube box (Figure 2.8). If possible, plan the fluorescent tube box so it works by directing the light downward onto a flat surface. Either the light box can be suspended over adjustable shelves, or the legs can be modified to suit. The optimum distance from the light to the printing frame can be easily adjusted. Additional advantages are that dodg- ing and burning in can be done by placing printers’ Rubylith material on the glass. Heavy glass plates can be substituted for the printing frame. Due to uneven lighting, many homemade fluorescent light sources will produce scalloping effects on skies. Simply move the printing frame sideways every few minutes to avoid this. It is also possible to purchase manufactured UV light boxes. Some are available with vacuum easels. transmission densitometer. However, unless research is Sources of well-made, professionally constructed light contemplated, a reflection densitometer is not needed, boxes are listed in the “Sources” section. (Sources: AR, nor are the filters. After delving into Part Two: BS, EE, PC, VCS) Sizes range from 11 x 14 to 20 x 24. Sensitometry for the PlatinudPalladium Process, you Prices vary from $400 to $3,000. might consider a purchase, or at least share one with a photographer friend. Some models come with both modes, as well as a COMMERCIALPLATE BURNER bank of filters for color separation work? Many print The commercial plate burners used in the graphic arts shops are going totally digital and are purchasing den- industry-if one is within your budget-are the ideal sitometers that link directly to computers. Therefore, choice. (See Chapter 9: The Platinum and Palladium there are many fine older-model densitometers on the Print, Figure 9.17.) Many come with a vacuum easel. used market. A good source is eBay (http:lliuww. The light is collimated from a reflecting surface to give eba y. corn). even distribution over the entire field. Most come with There is also a separate class of densitometer that light integrators, which are timers based on units of reads the UV spectrum of light. This is particularly light, so fluctuations in current do not affect printing important for photographers who develop their nega- times. They draw considerable 110-volt power and, tives in pyro, because the yellow stain does not therefore, require a separate circuit breaker. A perfect accurately register on normal densitometers, which choice is the NuArc 26-1K or table 26-1KS model,4 each read the entire spectrum, negating the effect of the of which comes with a 24 x 26-inch vacuum easel, for stain (see Appendix D: Pyro and Platinum Printing). approximately $1,500 to $2,000.

MODIFYINGA LIGHT METER DENSITOMETERS Using the instructions in Phil Davis’ book Beyond the Zone System (1998), you can convert a Pentax or Densitometers read either transmission or reflective Minolta 1’ spot meter to both a transmission and densities. To maintain control in this costly process, reflection densitometer. many platinum printers eventually find that they need a

’. NuArc has now replaced the mercury vapor light in the 26-1K model .’. An important consideration is the length of the densitometer’s arm. with a metal halide bulb, calling it the 26-IKS. The 26-IK will still be which must reach to the center of your largest negative. hfany of the made on special order and parts remain available. (Source: NA) less-espensive models will only read full negatives up to 8 x 10 inches. 14 THE PROCESS

INEXPENSIVETABLE~MODEL DENSITOMETERS Transmission densitometers costing from $400 to $1,500 are available. Some are quite flimsy. The German-made Heiland TRD 2 is both a trans- mission and reflection densitometer for $995. The measuring-throat length is four inches, which allows it to be used only with negatives 8 x 10 and smaller. (Source: VCS)

HAND~HELDDENSITOMETERS X-Rite makes portable, battery-operated units (Source: XR):

Transmission Model 331 $1,000 Refection Model 504 $1.890

(The older 400 model may be available in the used market.)

Hand-held densitometers are quite convenient, but they come with only a 6-inch arm that makes the reading of ultra-large negatives difficult. Because of their compactness, the reading circle is quite small. At times it is hard to position the area to be read (Figure 2.9). Other suggested choices are as follows: (Source: 01) X-Rite 810 (This is a transmission and reflection densitometer that costs $3,620 new.) THE PROFESSIONALMODELS Gretag D-200 I1 (Made by Gretag-Macbeth, this Eseco Speedmaster densitometer leads the industry UV transmission densitometer costs $2,663 new. (Figure 2.9). The units come with extensive warranties, (Source: GR) Optional tubes are available, includ- as well as an efficient customer-support service. Models ing a UV head. This model reads at 373 nm.) starting from $500 will attach to your computer. Eseco’s Ortec Model 4310 UVNIS densitometer (Source:01) table models are more expensive, but they are worth X-Rite 369 (339 in Europe) every penny. I recommend a used Model T-85D. They X-Rite 361T transmission densitometer UV & are made so well that if you can find a used one- Ortho (This comes in transmission only and costs particularly the TRC-60D dual model-snatch it up. $2,750 new. It reads at 380 nm. See also Appen- (Source: ES) dix D: Pyro and Platinum Printing, Figure D.7.) 15 16 9 THE PROCESS

For the negative-positive printing process, Ansel Adams since camera settings of the length of exposure and used a musical analogy to refer to the negative as the aperture are spaced in the same intervals. The range of score and the print as the performance. No amount of light transmitted by the shadow and highlight portions technical skill or virtuosity can redeem a poorly written of the negative is the density range (DR). musical composition, and the same can be said for photography. In the parlance of our times, we can use \( 1 I I : For a full tonal range print, the DR of the negative the computer term “garbage in, garbage out” to convey must match the ES of the particular paper grade to be the same meaning. used. Becoming a successful platinum or palladium (PtPd) An appeal: One of the pitfalls in the study of any printer demands that the production of negatives be photographic science is the tendency to produce some under control.’ Unless one is into more avant-garde “techno-fascists’’ who are more interested in nianipulat- methods of expression, or relying on a totally computer- ing materials than engaging in visual expression. Photo- generated negative, there are no shortcuts to this. A graphy is, however, an inexact science because of the basic knowledge of the properties of light-sensitive many variables beyond our control. If we keep sight of materials is required. This involves a working knowledge the purpose of our endeavors-to produce photographic of photographic sensitometry. While the very concept images by the exercise of the right side of our brain- may be intimidating to some, the principles needed we can allow the left side to help out without taking for the basic practice of photography are surprisingly over. simple. The printing speed of hand-coated platinudpalla- dium emulsion is approximately one million times slower than modern silver paper. No practical enlarging units PHOTOGRAPHICS ENs ITOMETRY are capable of producing enough light to properly expose PdPd paper. It is, therefore, a contact printing process. Photographic sensitometry is the science related to the Unless steps are taken to produce an enlarged copy reaction of light-sensitive materials to exposure and negative, the size of the finished print is determined by development. Anyone who pushes the button on a the format of the camera used. camera engages in the application of sensitometry. If one The PtPd process shares another characteristic were to go into the collection archives of any great common to the nineteenth- and early twentieth-century photographic museum and choose six photographers at photographic printing processes. The negative densities random, the chances are overwhelming that each has to produce both shadow and highlight print values must mastered the sensitometry necessary for their art. As be of a greater range than those required by modern with accomplished painters, sculptors, and musicians, silver gelatin paper. Pt/Pd paper, therefore, has a greater each has studied and become proficient in the char- exposure scale (ES) than silver gelatin paper (Todd and acteristics of their materials, be they paint, structure, or Zakia, 1969; Crawford, 1979; Davis, 1998; Kodak, the timbre of the musical instrument. Strangely, some 1998). photography students, particularly if they have not had As the print is the final product of the negative- some basic math and chemistry courses, are reluctant to positive photographic process, the exposure and develop- learn the technical aspects necessary for control of light- ment of the negative must be tailored to fit the exposure sensitive materials. Fortunately, most young photogra- scale of the paper. The relative amounts of light passed phers, as they become immersed in their forms of through the negative during the exposure of the paper is expression and are confronted by the cost of wasted measured in multiples or divisions of two. This concept materials, will learn sensitometry indirectly by problem is also used during the exposure of the negative to light, solving. The following is a rather elementary discussion of the principles of sensitometry as applied to the PtPd process. Purists may find that some of the informa- ’. As discussed in Appendix E: Crafting Digital Negatives for Contact tion presented is not entirely accurate. However, Printing Platinum and Palladium, even if contemplating the generation photography when practiced as an art form is an of digitally enlarged negatives, the making of a good original negative imprecise science. Most of the materials and equip- is no less important. Relying on Photoshop” to salvage inadequate negatives may result in considerable loss of data as well as the need to ment we use are only accurate within tolerances of generate artificial imagery to compensate for information lost due to plus or minus 10%. (Check the guarantee of the improper exposure and/or development. shutter speeds of your lens.) It is our goal to control the process to the best of our ability, so that the subject brightness range. Replaces ASA (American errors inherent in the process are not compounded. Standards Association). For this purpose, it is highly desirable to have a Lens Flare: The effect of extraneous light within working knowledge of sensitometry. the photographic image caused by lens elements and reflected from within the camera. The flare effect, added to base fog, determines the DEFINITIONS beginning of minimum useful shadow density of a Average Gradient (G): One of the measurements negative. used to determine the slope of the characteristic Logarithm (log): An exponent of the number 10. curve made by plotting the transmission density of a film in relation to the amount of exposure to light. Other methods used are the Contrast Index TRANSMISSIONDENSITIES (CI) and Gamma (y). They are discussed in the recommended texts (Davis, 1998; Todd and The amount of light passed through a negative can be Zakia, 1969). measured quite simply with a traizsmission deiisit- ometer (see Figure 2.9). The portion of the negative to Base plus Fog (B F or b f): The transmission + + be read (usually a 1-mm circle) is placed over a pin- density of portions of the negative unexposed to sized light source, and a button is pushed. A number is subject light. given either by dial or digital readout. Numbers are Subject Brightness Range (SBR):’ The range of interpreted based on the Logarithmic System of reflected light produced by the subject to be photo- Measurement. graphed. It is generally determined by the use of a spot meter to measure the limits of textured shadow LOII values and highlight areas. The difference is nor- A good transmission densitometer can be obtained mally expressed in stops or logs (multiples of 0.3). for the same amount as a good enlarging lens. When measured as a ratio, it is referred to as the (See Sources section.) Its use allows technical Subject-Luminance Ratio. control, which greatly cuts down on the number of Density Range (DR):The transmission densities of a prints destined for the “round file.” If one delves negative, which represent the image to be exposed to into Pt/Pd printing for any period of time, the photographic paper. It is determined by subtracting resulting savings will shortly pay for a transmission the shadow density from the highlight density. densitometer. Effective Film Speed (EFS):The optimum film speed For those not inclined to purchase a densitometer, a when adjusted for variations in development. “Visual Comparison Densitometer” can be utilized. This is simply a portion of dark cardboard through Exposure Scale (ES): When applied to photographic which a small round hole has been punched. It is paper, it is the range of light needed to produce a used for assessing transmission densities with a step full tonal scale print for a particular process and tablet for reference (see Chapter 8: Calibration, contrast grade. It is also referred to as exposure Figures 8.4 and 8.5). range (ER). IS0 (International Organization for Standardization): A value for film speed assigned by THE LOGARITHMICSYSTEM the manufacturer relating to exposure at a given If DR and ES were to be expressed with actual arithmetic numerical values, such as 2, 4, 8, 16, 32, 64, 128, and so on, the numbers would soon become ’. The use of a spot meter to identify and place “Zones” is beyond the scope of this text. Nevertheless, unless one is photographing in a set unwieldy. We use the shorthand system of logarithms lighting system (i.e., a studio), some method must be used to accom- (logs). A logarithm is a power of 10 rather than a modate varying lighting conditions. Most often, this involves reading numerical value. selected areas of reflected luminance with a spot meter. These values For example, we know that 10 times 10 is 100. This are “placed” in values of black. gray, and white to plan the finished is and is expressed in as 10’ Also, print; this is the process of pmkdiziltion. Differences in the SBR will 10 squared logs dictate development times and concentrations so a standardized, 10 x 10 x 10= 1000, which is 10 cubed, or lo3. The usable negative can he made (Davis, 1998; Schaefer, 1998). superscript number is the exponent or power. 18 THEPROCESS

If decimals are used to denote fractions, a number THE DENSITYRANGE FOR A PLATINUMOR can be found to represent multiples of two: PALLADIUMNEGATIVE If the number is the numerical value is 2. Platinum or palladium paper has a greater ES. The is twice the value of 10.’ and, therefore, equals 4. average or “grade 2” equivalent paper has an ES of 1.4 10.’ is three times the value of 10.’ and equals 8, and for a Pt/Pd mixture and 1.65 for pure palladium. so on. Therefore, to make a full tonal value print, we must If we now drop the 10, logs can be expressed in a match the negative DR to the paper ES. As with silver simpler manner: printing, a less contrasty negative will require a higher grade paper, and a more contrasty negative a lower becomes 0.3 grade.3 For those new to the process, however, it is 10 becomes 0.6 better to make a negative suitable for a middle grade of 10 becomes 0.9 any paper and only use the other grades to compensate becomes 1.2 for the many variables in photography that may account for a less than “perfect” negative. Using this system, large numbers such as 10,000 can be expressed as 4.0, and 100,000 as 5.0. Note that to multiply or divide by 2, one simply adds or subtracts 0.3 NEGATIVECONTRAST VERSUS to or from the log. NEGATIVEDENSITY A lens aperture or stop of fl5.6 lets in twice the amount of light as f/X. F/11 lets in half the amount of EXPOSURE light of f/8, and so on. Thus, in photography, the word stop is also used to represent multiplications or divisions The working negative contrast is derived by subtracting of 2. the shadow values from the highlight values. The Using this system, paper ES and negative DR can be inherent transmission density of the Estar base of a expressed in logs. The ES of grade 2 silver paper negative and the minute portions of the unexposed silver expressed in logs is approximately 1.1, or 3 and 2/3 salts reduced at development is called base plus fog stops. Therefore, the shadow areas of the paper require (B + F). This will be found at the edges outside the image 3 and 2/3 the amount of light as the highlights. The ES frame. of grade 3 paper may be 0.9, which requires three ranges Within the image area, lens flare must be added to of stops. The DR or contrast of the negative must match the inherent B+F density of a negative. At the instant these values to produce a full tonal value print. the image is projected onto the film, lens flare from reflections within lens elements and the camera body adds a diffuse halo of light to that of the image. The amount of lens flare is dependent on the lens and camera design. View cameras and lenses contribute enough flare TABLE 3. 1 Tkt LOG EQL~IVA~VT~ that this must be taken into account when calculating exposure and development. Once the film becomes Lon Nirmerical Value stops sensitized to where the silver salts become reactive to 0 0 increases in light, the actual image projected by the lens 0.3 2 1 begins to register, and a Threshold is reached. It is at this 0.6 4 2 point that useful shadow density begins. 0.9 8 3 Base + Fog Usually 0.1 to 0.2 1.2 16 4 + Lens Flare Factor Usually 0.02 to 0.04 1.5 32 5 1.8 64 6 Threshold for Shadow Usually 0.15 to 0.25 2.1 128 7 Density 2.4 256 8 2.7 512 9 3.0 1,000 10 4.0 10,000 100 3. More than 1s platinum and palladium “paper grades” can he 5.0 100,000 1,000 achieved by varying the concentrations of restrainer and the combinations of metal. Since B+F and lens flare contain no information, for Film. TXT Developer: D-76 most imagery they are not considered in planning a print. Temperature. 70F Time, (minutes)’ 4.6.9.14.20.20885‘F Depending on film and development, it is not until a 21 shadow density of 0.2 to 0.4 is reached that it becomes useful. Since this “magic number” determines printing time for both silver and platinum, it should be our goal. This is accomplished by proper exposure in the field or 1.2 studio. Correcting shadow areas by altered development 0.9 2 techniques is difficult to impossible. Too little exposure s 0.6 $ results in the valueless areas just discussed; too much 0 will result in lengthy printing times. For the purposes of 03 p this text, we have chosen 0.3 to be an ideal shadow 0.0 density. 30 27 24 21 18 15 1.2 09 06 0.3 0.0 Light Increase b

While silver paper exposures are measured in FIGURE 3.1 A FAMIIYof CURVESAPPROPRIATE TO PLATINLIM/ seconds, platinum exposures are calculated in minutes. PA[[AdIuhi PAPER( COLIRTESVof Phil DAVISPIOTTER PRO~RAM~) A two-stop error in the exposure of a platinum negative may easily result in a 45-minute printing time!

DEVELOPMEN] increasing the normal development procedure. In densi- It is in the highlight areas that negatives are “con- tometric terms, less development will produce a lower structed” by selective development for the chosen print contrast, or average gradient. This is done to compen- media. As all photographers learn, this is accomplished sate for a subject brightness range of more contrast by changing developing time and/or concentration. (from eight to 12 or more stops). Conversely, a negative Increasing development time and developer concen- made from a “flat” subject, with a range of four to six tration will increase the transmission densities of stops, can be structured to fit photographic paper by negative^.^ The thinner shadow densities will be less overdeveloping. This is the basis of Zone System affected. The more dense, or highlight, areas will be photography. changed far more significantly. (See Appendix B:

The Large Negative, and Appendix C: Some Film/ . I A word about the Zone System: Ansel Adams did Developer Combinations to Produce a Platinum/Palla- not invent photographic sensitometry. He and his dium Negative.) colleagues simply implemented a language to measure If a film is given a series of developer/time the reflective values of the subject matter that will be combinations, the changes can be plotted to produce a translated by way of a negative to the reflected grays of a Family of Curves (Figure 3.1). monochromatic photographic print (Schaefer, 1998). Note in Figure 3.1 that as the development times In calculating negative values with a transmission increase from 4 to 20 minutes, the lower shadow areas densitometer, both the useful highlight (Zone VIII) and remain relatively unaffected, but the more dense highlight the useful shadow densities (Zone 111) are measured. areas change considerably. By increasing development After simple subtraction, the difference is determined, over that usually used for silver negatives, we achieve the which represents all the intermediate values. This is the contrasts necessary for the PtPd negative. DR of the negative. Useful highlight density -Useful shadow density = DR THE NEGATIVEDENSITY RANGE While the “ideal” silver negative may be 1.4-0.3 = In addition to the advantage of faster speeds, modern 1.1, the Pt/Pd negative will be 1.7 - 0.3 = 1.4. The nega- films allow control over the DR by either decreasing or tive for a palladium print should be 1.95 - 0.3 = 1.65. Note that regardless of the process and negative 4. This will be discussed in more detail in Chapters 12 and 13 of Part Two: Sensitometry for the PlatinumlPalladium Process. You may wish requirements, the shadow densities should remain to peek ahead if you are curious about this phenomenon. approximately the same. 20 THE PROCESS

OVER, AND UNDEREXPOSED NEGArlVES The negatives previously discussed have proper contrast SBR 7 (Stops) for the paper to be employed. If, in the construction of a Pt/Pd negative shadow values are overexposed, and then the film is subjected to the increased development II 111 IV V VI VII Vlll IX necessary for greater contrast, the minimal effect noted by development on shadow areas will rapidly become significant. A totally dense or “bulletproof” negative may result. This negative may be worthless, even Density Range 1.05 using reduction techniques. Conversely, a grossly under- - Opacity Ratio 11 .I exposed negative, contrary to the claims made by manu- THE SILVER NEGATIVE facturers, cannot be “pushed” to the point where shadow values become adequate.

USING A PORrlON OF THE PAPER SCALE / SILVER PHOTOGRAPHIC PAPER \ Until now, we have been discussing the requirements to make a negative that will exploit the complete range of values available for each particular paper: the full tonal value print. For more accomplished photogra- phers, this may not be the goal, and they may plan accordingly. Many subjects, particularly portrait subjects, can be better expressed using only a portion of the tonal scale. Platinum and, in particular, palladium are quite adap- table to images that occupy the elegant high- and mid- Note that the negative must be constructed to match values that the paper is capable of rendering. For this, the ES of silver gelatin paper. In this case, it is contrast the DR of the negative may be less than the ES of a grade 2. The reflective density5 of the final silver gelatin particular grade of platinum or palladium paper. A DR print is 1.8 (six stops), considerably more than can be of a typical negative for silver paper (1.l) or less can be obtained with Pt/Pd. Under certain conditions, and with used with exquisite results. (See Using Portions of the toning, a silver gelatin print can be brought to a Paper Curve in Chapter 13: Using the Print Curves.) reflective density of 2.1! For a typical platinum or palladium paper with an ES of 1.4, the required opacity range of the negative is EXPOSINGAND DEVELOPINGTHE PLATINUM 30:1 (Figure 3.3). OR PALLADIUMNEGATIVE As the ES of Pt/Pd paper is greater than that of silver Manufacturers of photographic film have determined gelatin, a negative of more contrast is required. At a that the brightness range of a typical outdoor subject given subject brightness range, proportionately is seven stops, which is a logarithmic value of 2.1 or more development is needed. a subject-luminance ratio of 128:l. When transferred Because of the greater DR of the negative, the values to a transparent negative, the range must be compressed of transmission densities are spread over a greater to match the photographic paper to be used. For modern useful portion of the negative silver emulsion. silver paper, the compression must be extreme, down to This allows for more subtle tones to be transferred a DR of 0.9 to 1.05, or an opacity range of 11:1 (Davis, to the paper. This is seen in the final print as a 1998; Kodak, 1998; Schaefer, 1998). This is illustrated smoother distribution of rnidtones and whites. Also, in Figure 3.2. The subject is measured in stops, SBR, or subject- ‘.The reflected grays of a photographic print can also be measured luminance ratio. with a ref7ectiiv drizsifovzefer.This machine is considerahly more The resulting compression of the negative is expensive than its transmission counterpart. Unless one is doing studies of photographic papers. a reflective densitometer is not necessary, as measured in stops, DR, or opacity ratio. the human eye is much more sensitive and can he trained to identify The final print is measured in reflective density reflected values. For a discussion of this phenomenon, consult range or reflection opacity ratio. Chapter 8: Calihration. SBR 5 6 (Stops) SBR 7 (Stops) -t +- +- Subject Luminance Ratio 60 1 - tSubject Luminance Range 1.68 V SUBJECTWITH LOW SBR

111 \I \I11 \1111 I”

\ More Development (N+I) 1 THE 1.4 DR PffPd NEGATIVE 4- 4- Density Range 1.4 -b . -Opacity Ratio 30:l THE PVPd NEGATIVE- /’ -\ \ / Less Develonment IN-1) \

VI VII Vlll IX x XI SBR 8 6 (Slops) b PVPd PHOTOGRAPHIC PAPER Subject Luminance Ratio 425 1 t Subject Luminance Range 2 6 b SUBJECT WITH HIGH SBR Reflection Density Range 1.5 Reflection Opacity Ratio 321

conclude that N + 1 would be synonymous with an SBR of 6 (6+ 7=N+ 1). That is not the case. With expansion development, one zone is simply not kicked because of this property, the medium-low and into the next. All zones are expanded proportionally. midtones of the subject (Zones IV and V) are more Therefore, the SBR for N + 1 development is somewhat accurately placed in the Pt/Pd print. (They tend to be lower than 6. If N + 1 development is indicated, the depressed in the silver gelatin print. See Chapter 12: actual modification would be SBR 5.6 -+ 7. For The Film and Paper Curves, Figures 12.14, 12.15, N + 1.5,6 it would not be 5 -+ 7, but SBR 4.2 + 7. and 12.16.) With contraction development, the same principles At best, the reflective densities of platinum or apply. N - 1 development is not 8 + 7 = N-1, but SBR palladium paper are two to three stops less than that 8.6 + 7. An N-2 is SBR 10.5 + 7. N-3 is SBR 12 + of the silver gelatin print. This characteristic is 7. A more complete presentation may be found in Davis’ more than compensated for by the depth of the Beyond the Zone System (1998). hand-coated image and the qualities described previously. DEVELOPMENTFOR SUBJECT BRIGHTNESS RANGES

NOll: Minor White, teacher and photographer, used the The low 5.6 SBR requires more development than the term convincing black to describe maximum paper normal 7 SBR to make a negative with a 1.4 DR. In blacks. When looking at a monochromatic print, the Zone System terms, this is an N+l development viewer interprets all tones in comparison to the others. (Figure 3.4). The high 8.6 SBR requires less development Thus, a well-printed black will be seen by the mind as (N-1) than does the normal 7 SBR to make the same black, even though it might register poorly on a machine negative. With proper technique, both extremes of SBR (Todd and Zakia, 1969; Adams, 1981). can be managed to produce negatives with essentially identical transmission characteristics.

ZONESYSTEM DEVELOPMENT COMPARED TO SUBJECI BRIGHTNESSRANGE ‘. Because Pt/Pd negatives must be developed at a high average gradient For those using the Zone System, there may be some to accommodate the high ES of the paper, unless special techniques are used, it is generally not possible to increase the slope of the curve to a confusion regarding the “N” designation and the SBR. full N+ 2. (For selenium toning of the negative, see the end of this With N development, N = SBR 7. Some, however, might chapter and Chapter 4: Chemicals.) 22 9 THEPROCESS

THE LOW SlJ6lECl BRICHINESS RANGE a number of methods may be used. Comprehensive cover- We have referred to platinum printing as the art of age of such methods is beyond the scope of this text; adapting today’s materials to a historical process. however, I will make some reference to the average With all its remarkable characteristics, contemporary gradient to compare the effects of altering film develop- film does not have the silver content exhibited in ment. older films. Therefore, many films that are perfectly Increasing development time and/or concentration adapted for modern silver paper cannot be expanded steepens the slope of the curve and increases the average sufficiently by development to produce negatives in the gradient (see Figure 3.1). If one were to refer to average 1.4 to 1.8 DR necessary for platinum or palladium gradient numbers to compare slopes of the curve, a printing. These films reach a ganima infinity at which typical negative developed for silver paper would be at further development only increases overall density approximately .60. Platinum or palladium paper requires rather than DR. A list of recommended films may be an average gradient of .70 to .SO. If one needed to tailor found in Appendix C: Some FildDeveloper Combi- an overdeveloped “N + 2” negative for platinum, an nations to Produce a PlatinumPalladium Negative. average gradient of 1.10 might be needed. No film/ developer combination can accomplish this. Some cannot be developed to N + 1. Graphic reference to this THE HIGHSU6lECT BRlGH7NESS RANGE will be provided in Part Two: Sensitometry for the Because of the broader scale of the negative needed, it is PlatinudPalladium Process. less of a challenge with Pt/Pd to manage a high-contrast subject by using less development. When exposing at an EFS and using diluted developer, SBR as high as 14 can EFFECTIVEFILM SPEED be recorded on the PtPd negative (see Plate 3.2). Manufacturers assign each film an ISO. This IS0 is only applicable when the film is developed for a seven- AVERACE GRADIENT stop SBR for silver gelatin paper. If the film is A most effective means of quantifying the effect of overdeveloped or underdeveloped to increase or development is to calculate the slope of the film curve. decrease the slope of the curve, shadow density is also As indicated in the section of definitions provided earlier, affected. It happens to a lesser extent, but since shadow 21 assigning an EFS other than the IS0 determined by the manufacturer. Film: TXT 15 Developer: D-76 IS0 is set by the manufacturer at a specific SBR Time (Minutes): 4,6,14.20,20@85~F 12 and development time. If either is changed, a new value

092 of film speed, the EFS, must be used. m 3 06g Overdeveloping film can increase the shadow values 0 by more than one stop. This must be taken into account. 03: v) For overdevelopment, shadow densities are controlled by 0 o2 decreasing the exposure. This is best accomplished by 30 2.7 24~2111811.5 1.2 09 0.6 0.3 0.0 increasing the ISO. The new value is referred to as EFS.

EFS 640 320 160 Therefore, although the IS0 of Tri-X Pan Professional Exposure change needed to maintain textured shadows Film (TXT) is listed as 320,’ it must be understood that Decrease LIGHT Increase - - this value does not apply to the increased development needed for a platinum or palladium negative. For that processing, an EFS from 400 to 600 may be needed. At a high SBR, exposure must be increased to prevent the shadows from falling on the horizontal portion of the film curve (and producing no separation density determines printing time, small changes may be of values). With TXT, an EFS of 160 may be necessary. critical. While some films may not require such pronounced In Figure 3.5, a slightly diagonal line is plotted to changes, the same principles apply. Over- or under- identify the portion of the film curve where enough exposure by as much as one stop can significantly changes occur relative to light increases to cause tex- tured shadows (at about a transmission density of 0.3.). ’. Kodak Tri-X Pan Professional Film (TXT)has been replaced by 320 As development times are changed to compensate for Tri-X Professional (TXP).The exposure characteristics are similar, but various SBRs, exposure must be modified to keep shadow development times are increased. See Appendix C: Some Film/ densities under control. This is most easily done by Developer Combinations to Produce a PlatinundPalladium Negative. 24 THE PROCESS

affect the Pt/Pd image. The extent of the film speed Pt/Pd printing-when practiced as a hand-coated, change needed is largely dependent on the film used. print-making process-produces an image that becomes (See Appendix C: Some Film/Developer Combinations wedded to the structure and characteristic of the paper. to Produce a PlatinudPalladium Negative, Tables C.3 Sharpness, or lack thereof, is not generally noticeable, to C.12.) except through magnification.8 Even if it is, the other qualities previously described do not rely on mechanical \( )I i A simple rule for making a platinum negative is to sharpness to convey a message. increase development 1.5 times over what is required of a negative for silver paper. Concurrently, an increase of GRAININESS EFS of 1/3 to 2/3 over the published IS0 is required to control shadow value by reducing exposure. For a At the smaller apertures needed for large format photo- palladium negative, double both the development and graphy, a faster film is needed if one wishes to avoid the IS0. longer exposures and the resultant reciprocity failure. For cameras larger than 5 x 7 inches, higher speed films of IS0 320 or greater are desirable. The structure CHARACTERISTICSOF THE PLATINUM/PALLADIUM of the silver halide emulsion in films of higher IS0 NEGATIVE affects the graininess. Also, the high-energy developers and increased concentrations and time we must use to We have discussed some of the difficulties of making Pt/ produce a platinum negative further increases the Pd negatives and the measures that must be taken to “grain.” produce them; however, when a Pt/Pd negative of the With a hand-coated process, the increase of size and desired DR is produced, most of the other characteristics clumping of silver particles responsible for an increase in that often plague silver photographers become relatively film grain are simply not discernible under normal view- negligible. ing conditions. Visible film grain is also related to the degree of enlargement. Pt/Pd printers do not enlarge, SHARPNESS unless larger negatives are generated from smaller negatives. Even in that case, the qualities described in Many platinum photographers will eventually find that the previous paragraph more than compensate for the a larger camera is more suitable to their needs. Large graininess produced by the negative. cameras require lenses of longer focal length, frequently Graininess from the negative should not be confused with extended image circles to allow for view camera with granularity found in the platinum or palladium movements. Unless one is willing to pay a small fortune emulsion. This can be a serious problem, to the point for a monstrous piece of glass, less resolution and of degrading certain images. Methods to avoid this more aberrations are generally found in direct propor- are covered in Chapter 7: Choose Your Method, Chapter tion to the length of the lens. Moreover, for satisfac- 10: Advanced Technique, and Chapter 11: Problems. tory depth of field, small apertures of f/45 to f/90 are frequently used, further increasing the degree of aberrations. SCRATCHESAND PINHOLES It is best to avoid scratches and pinholes by handling \()If : Some process lenses work remarkably well at film carefully and keeping the camera as free of dust as apertures from f/64 to W128. Their maximum apertures, possible. However, if either a scratch or a pinhole occurs, however, are usually quite small, in the f/9 to f/11 range, one learns to further appreciate the many advantages of which makes focusing difficult. For my big cameras, contact printing. Since these defects will not be enlarged, I use a Fresnel lens. Good, inexpensive varieties can be treatment with Crocein Scarlet will take care of all but found at Edmund Scientific (ES).Placing the Fresnel lens the most severe. (Its use is discussed in Chapter 10: behind the ground glass will not significantly affect the Advanced Technique). When using photomechanical focus at small apertures, and this will protect the glass from breakage as well. Fortunately, with the increase in negative size, less If negatives are to he enlarged, either by photomechanical or digital means, ir may be necessary to avoid some of the lens aberrations enlargement is practiced, negating the visual effects of characteristic of siiialler apertures. A compromise may be necessary to these disparities-particularly when the final presenta- plan less depth of field in favor of choosing an aperture closer to the tion is in one of the nonsilver processes. optimum for a particular lens (usually f/16 - f/32). enlargement techniques requiring multiple steps, the stain produced is approximately the same as the problem may be acute, as each step adds a new layer of complementary color used to selectively block transmis- blemishes. sion to the blue-sensitive paper. Consequently, negatives of much less development can be used over their unstained counterparts. Since less density is required in THE CIRCLEOF CONFUSION highlight areas, graininess is diminished. Pyro negatives The ability to discern “sharpness” and “grain” is related are also said to produce more edge sharpness. to the ability of the naked eye, at a certain distance, to The negative, when developed in a solution con- distinguish a circle from a point. This is called the circle of taining both pyrogallol and the conventional Metol confusion (Stroebel, 1993). As the distance from the developing agent, is doubly developed. The transmission viewer to the print increases, this distinguishing ability is density is produced by both the selective reduction of diminished. Studies have shown that, in an exhibit space, silver particles as well as a “tanning” effect produced by viewers tend to establish a distance twice that of the pyrogallol. In the thinner areas of the negative, little diagonal dimension of the artwork. It is from this posi- effect is noted, but as the midtones and highlights are tion that (it is hoped) the content of that work becomes reached, the yellowish stain adds as much as 50 to more significant than the degree of technical perfection. 100% more effective transmission density (Hutchens, 1991). One must bear in mind, however, that a properly THE USEOF SELENIUMTONER TO INCREASE developed negative made by more traditional means NEGATIVECONTRAST may accomplish the same purpose. Nevertheless, in low SBR, the pyro stain may more efficiently bring a nega- Negative DR can be increased by 0.1 to 0.3 by selenium tive into the Pt/Pd printing range. In an extreme N+2 toning,’ without an appreciable effect on shadow den- situation when even more strenuous development sity. This may be enough to bring a marginal negative may be required, pyrogallol staining may solve the into platinum range, or move a Pt/Pd negative into problem. palladium range (see Plate 3.3). The final assessment as to the superiority of After washing, immerse the wet negative in a 1:3 pyrogallol must remain in the hands of the photogra- solution of Rapid Selenium Toner to distilled water. pher. For some, the use of the pyrogallol negative is the Agitate constantly for 5 minutes and rewash. Take care route to effective image making. before subjecting an unread negative to selenium toning. However, those just investigating the Pt/Pd process A wet negative viewed through a ceiling bulb looks a lot are urged to first spend sufficient time learning to thinner than it will eventually test after dry-down. effectivelyuse one of the appropriate filddeveloper Injudicious selenium toning may blow the negative even combinations ’” (see Appendix C: Some FildDeveloper beyond the capabilities of palladium paper. Until consi- Combinations to Produce a PlatinudPalladium Nega- derable experience is obtained, it may be more prudent to tive). Once an effective filddeveloper combination is study the dried negative before selenium toning. Simply found using standard developers, pyro can be investi- soak it in water for 5 minutes before toning. The effect gated for comparison. Many Pt/Pd printers, the author may not be as pronounced as immediately following included, have found that with Pt/Pd printing, many of development, but it is much more judicious. the reported advantages of pyro development can be duplicated using more traditional methods. THE PYRONEGATIVE

\( )I ! See Appendix D: Pyro and Platinum Printing. The use of pyrogallol for developing negatives is at least as old as the platinum process. The yellow-green

111. As Rob Herbst states in Appendix D: Pyro and Platinum Printing, “Stain is your friend. Stain is your enemy.” Pyro development for a Ptl Pd negative requires a hit more finesse than that for a silver print. A ’. Selenium is a tosic heavy metal. Use only in a well-ventilated space. slight error in staining can raise the ultraviolet (UV) blocking effect of The use of ruhher gloves or print tongs is strongly recommended. shadow density to printing times of more than an hour. Thispageintentionallyleftblank PLATE 4.1 6AICkAwANA BAYhlrh REFds, ONTARIO.CANAdA 1997 12 x 20 INC~Pd

27 28 THE PROCESS

THE REASONABLEAND PRUDENTUSE Four categories of potential hazards are outlined in the MSDS information: Chemical safety is based on a reasonable and prudent Health: Toxic effects of a substance if inhaled, use of chemicals. Platinundpalladium (PtPd) printing is one of the safest of all the photographic processes. The ingested, or absorbed chemicals used in significant quantities are inorganic Flammability: Tendency of a substance to burn salts, oxalates, and high dilutions of weak acids. More Reactivity: Potential of a substance to react violently hazardous compounds are used in infinitesimal amounts, with air, water, or other substances most often measured by eyedropper. For the most Contact: The danger a substance presents when it dangerous substances listed in the literature, satisfactory comes into contact with skin, eyes, or mucous substitutes exist. membranes Of these categories, the platinum printer will be most concerned about the following. A numbering THE MATERIALSAFETY DATA SHEET system from 0 to 4 is used in MSDS data to designate the degree of hazard. Each chemical is accompanied by a Material Safety Data Sheet (MSDS). Although the information therein is of considerable value to the PdPd printer, it is from the HEALTH indiscriminate use of this data that many of the scare 0. No hazard tactics about our process have been formulated. If each 1. Slight hazard chemical used in Pt/Pd photography is intelligently 2. Moderate hazard analyzed with photographic practice in mind, safe 3. Severe danger guidelines can be set up individually without a “one 4. Deadly, life threatening solution fits all” mentality.

CONTACT

WARNINGAND DISCLAIMER 0. No contact hazard to normal, healthy tissues 1. Slight hazard: irritant to sensitive tissues The following material in no way constitutes a 2. Moderate hazard: irritant to sensitive tissues; recommendation to deviate from standard regulations damages tissue and requirements for the safe handling of chemicals. It 3. Severe danger: destroys tissue, including skin represents the author’s own personal philosophy and 4. Extreme danger: life threatening procedures. All of the chemicals described in this text can be potentially harmful, particularly if misused. The In addition, the chemicals are indexed by relative toxi- reader is advised to inform him or herself in advance of city: The lower the LD50 (which is the oral dose that will any dangers and to take appropriate precautions. Such kill 50% of laboratory animals) for a particular chemi- information can be obtained from the MSDS of each cal, the more the potential risk. substance or by consulting any reference manual on che- Here is a helpful classification and summary of the mical safety. Furthermore, for any person to be in MSDS system and categories incorporating the various contact with these chemicals, a thorough review of MSDS ratings for chemicals: personal health should be obtained to rule out allergies MSDS 1-Those that, under normal usage, are and to be aware of possible teratogenic effects in the case basically harmless of pregnancy. With chronic smokers, many of the MSDS 2-Those that require some degree of natural defense mechanisms of the body are seriously caution in handling impaired, aggravating the effects of exposure to chemicals. It is also assumed that children and irrespon- MSDS 3-Those that can cause considerable harm sible adults will be shielded from contact with these through some or all the routes by which a chemical agents. can enter the body The author hereby denies liability for any subse- MSDS 4-Those that are extremely dangerous; it is quent injuries resulting from the use of the information recommended that they not be used in the PdPd contained in this text. process As each chemical group is discussed in this text, formulas have retained the British units; however, for these classifications will appear with pertinent informa- ease of mixing and determination of concentrations, the tion and precautions in italics. If questions exist, the metric system is superior and has been used here reader is encouraged to check the MSDS data for whenever possible. A short guide to the more common specific chemicals. conversions follows (Anchell, 1994). WEIGHT VOLUME 16 ounces = 1 pound 32 ounces = 1 quart N HRO M AT I Mo oc c FILM DEVELOPING 453 grams = 1 pound 1 quart = 0.95 liters AGENTS(MSDS 2) 2.2 pounds = 1 kilogram 1 gallon = 3.78 liters 1 ounce = 28.35 grams 1 ounce = 29.5 milliliters Although not specifically part of the PtRd process, some 1 gram = 0.03527 ounces discussion is in order regarding monochromatic film = developers. It is beyond the scope of this text to list all TEMPERATURE C =CELSIUS F FAHRENHEIT of the organic agents used for this purpose; therefore, Boiling (at sea level) 100' 212" generalities must be made. Freezing 0" 32 The most common agents are Metol (Elon, mono- 20' 6 8' methyl para-aminophenol sulfate), and Hydroquinone 38" 100' (para-hydroxy benzene). Many similar phenolic and (C x 9/5) + 32 = degrees F (F- 32) x 5/9 = degrees C benzene compounds are also found in developing agents. As a group, monochromatic film deueloping THE METRICSYSTEM agents represent more cause for concern than most of the chemicals used in the PtlPd process. The metric system encompasses measurements of Contact with skin should be avoided. When weight, volume, and length. All terminology is interrela- using the slightly alkaline film developers, ted and expressed in units of 10. In the case of distilled surgical gloves are quite effective (see Appendix A: water, for example: The Chemistry of Developing, Contrast Control, and Clearing Processes). It is entirely 1 cubic centimeter (cc) of distilled water = 1 milliliter (ml) and weighs 1 gram (8) possible, following continued skin contact, 1,000 g = 1 liter (I) and weighs 1 kilogram (kg) that contact dermatitis may develop, which may 1 g or 1 ml = 0.001 or 1/1000 of a liter or 0.001 of 1 kg necessitate a change to other agents. Full-time workers should consider the use of tube or JOBO A simple but effective way of determining concentra- methods (see Appendix B: The Large Negative). tions is to work in units of 1,000 rnl (1 liter). Realizing In some literature, pyrogallic acid (pyrogallol, that a percent is units/100, simply put the weight in grams 1,2,3-trihydroxybenzene)has been listed as more of volume in milliliters over 1,000, and remove one zero toxic than it may actually be. Utilize the same from each side of the equation. For example: precautions as listed previously. A Rollo Pyro is 1000 g = 1000 ml now available from Bostick and Sullivan (BS), which can be used with a JOBO processor. See Appendix D: Pyro and Platinum Printing for pyro formulas. This method, although not exactly precise, is For a brief description of the chemical reactions adequate for most photographic processes. involved in the Ptffd process, see Appendix A: The For a more chemically correct method, the for- Chemistry of Developing, Contrast Control, and Clear- mula is: ing Processes. weight of compound % = 100 x total weight of solution ABOUTMEASUREMENT UNITS

it The Pt/Pd processes were developed in England, so '. As solutions are mixed, variations between volume and weight is natural that many measurements are expressed in measurements occur; however, for most photographic processes they the British as well as U.S. units of measure. Some are negligible. 30 THEPROCESS

PURITYOF CHEMICALSAND WATER THE COATINGSOLUTIONS

Chemicals are available in differing grades of purity. For Usually for the paper coating, equal parts of sensitizer coating paper and toning techniques, reagent or analytic (ferric oxalate) and metal salts are combined. In addi- grade should be used. It is recommended that these tion, a restrainer (oxidizer) may be incorporated to chemicals be obtained from specific suppliers of plati- control contrast. num and palladium materials (see Sources section for The most common method is to place minute amounts of oxidizer (restrainer) into a second solution suggestions). For the chemicals used in larger quantities of sensitizer (A+B or Ratio Method). (See Chapter for developing and clearing, technical grades may be 7: Choosing Your Method.) By varying the proportions used. of pure ferric oxalate (A) and a similar solution with Distilled water should be used for the mixing of restrainer (B), more than 13 contrast grades are possible coating agents and developers. If tap water is relatively free of impurities, it can be used for the clearing agents for each metal or combination. One may also control and wash. If you have significant impurities in your contrast by putting the restrainer in the developer, thereby eliminating the use of sensitizer B (Dichromate water supply, consider a water softener, as conventional photographic filters may not do the job. Method). Recently, another contrast control agent, sodium hexachloroplatinite (Na2 or Pt IV) has been added to the list of oxidizers amenable to the PdPd process. Its use will be discussed in detail throughout this text. SIZING OF PAPER The metal salts (C), are either platinum, palladium, Presently, a wide choice of papers are available that or a mixture. Most “platinum” prints made today are do not need sizing (see Chapter 5: Paper). For those actually a mixture of platinum and palladium. Pure who wish to experiment with papers not completely platinum salts are not entirely amenable to a ferric amenable to the Pt/Pd process, many undesirable char- oxalate sensitizer, but they may work better with ferric acteristics can be overcome with starch or gelatin ammonium oxalate in the presence of moisture. Since sizing. The starch used is simple arrowroot starch print tone or color is largely determined by the choice of (MSDS 1). developer (see Chapter 10: Advanced Technique), for For gelatin sizing, Knox or Bloom gelatin is used. most practical purposes, a mixture of platinum and (See Appendix G: Elements of Platinum and Palladium palladium salts will be indistinguishable from a pure Printing.) Be aware that gelatin can burn severely if platinum print. A further advantage of combining metal allowed to contact skin when at high temperatures. salts lies in the cost of materials: Depending on market More significantly, Formalin is used for a final “fix” to prices, palladium is usually approximately 1/4 to 1/2 the harden and make the gelatin impervious to microbial price of platinum. growth. A print made with pure palladium is unique in tone In some cases, alum can be substituted for Formalin and character. It is best developed in potassium oxalate in the sizing process. (See Platinum 6 Palladium and is most responsive to restrainer placed in the Printing, 1st edition, Appendix E: Sizing of Paper.) sensitizer. In this text, only pure palladium printing and 50% combinations of platinum and palladium will be covered in detail. Reference is made to varying FORMALDEHYDE23% (FORMALIN) (MSDS 3-4) Formaldehyde is extremely caustic to the skin and proportions of platinum and palladium in Chapter 10: respiratory tract. Advanced Technique.

OXIDIZING AGENTS* Oxidizers are used in the PdPd process to decrease the SOLUTIONSUSED FOR PAPERCOATING, exposure scale (ES) of PdPd or palladium prints. DEVELOPING,AND CLEARING

For those unfamiliar with the PdPd process, see Table 9.1: Algorithm for Platinum and Palladium Printing for Much of this discussion is derived from Contrast Control for Iron a brief summary of steps in the making of a platinum or Based Printing Processes by Howard F. Efner (2002). It is presented palladium print. with his kind permission. HYDROGENPEROXIDE printing, it was found to be an effective source of Hydrogen peroxide 3% can be used in the PtPd process. oxidation in pure palladium printing. (See Chapter 8: Unfortunately, it is unstable in solution, slowly decom- Calibration for the use of Na2 and Appendix A: posing to water. It can be used in small amounts to “clean The Chemistry of Developing, Contrast Control, and up” a ferric oxalate solution by reoxidizing trace Clearing Processes for the chemical reactions amounts of ferrous oxalate back to the ferric form. It is involving Na2.) not recommended for general contrast control.

CHLORATEES DEVELOPERS Potassium chlorate is a powerful oxidizer, which is added in minute quantities to the ferric oxalate coating Several developing agents are available, including sensitizer B (either 0.6% or 1.2%). In the A+B Ratio potassium oxalate (warm tones) and ammonium Method, by changing the relative amounts of ferric citrate or Sullivan’s cold tone developer (cooler tones). oxalate A (no chlorate) and ferric oxalate B (miniscule In some processes, ethylene diamine tetraacetic amounts of chlorate), precise contrast control is acid (EDTA) and sodium citrate can be used for possible. development. Unfortunately, chlorates act differently based on the size of the cellulose paper fibers. In higher concentra- tions, graining or flocculation of the smoother tonal CLEARINGAGENTS areas of the image may be noted. When less chlorate is Most early literature discusses hydrochloric acid as a used in paper grades of longer exposure scales, the clearing agent; however, because of the danger in graining may be negligible, particularly in a pure handling this caustic material, I believe there are palladium print. When one attempts to use a negative satisfactory alternatives. of less contrast (typically a negative made for the silver Dilute solutions of phosphoric, oxalic, and citric gelatin process), the amounts of chlorate required can acids will be discussed, but further research into the badly deteriorate an image. effectiveness and archival properties of sulfiteEDTA makes them, in my opinion, the clearing agent of choice DICHROMA TEES for most papers. Potassium dichromate and sodium dichromate are effective oxidizers. Unfortunately, they are unstable in the coating solution. They are added in varying con- centrations to different containers of potassium oxalate COATI N G So LUT I o N s developer. This necessitates a different developer for each contrast grade desired. As with the chlorates, larger SENSITIZERS(MSDS 2.3) concentrations will flocculate the final image. FERRIC(FERROUS) OXALATE 27% FE2 (c202)3.5H20

SODIUM CHLOROPLATINATE FERRIC AMMONIUM OXALATE (NH~)TFE(C~O~)~.H20 Sodium chloroplatinate (Na2PtCl6) differs from the (MALDE/WAREPROCESS, ZIATYPE) potassium chloroplatinite (K2PtC14) used to make a platinum or Pt/Pd print. Sensitizers are salts of unstable iron compounds, Richard Sullivan of Bostick and Sullivan noted some containing oxidizing agents. Although it the mention of sodium chloroplatinate while perusing is possible to make your own ferric oxalate it can the historic literature. Although this form of platinum be a hazardous procedure. It is safer to buy it salt is not suitable for providing the platinum to make already formulated. The salts can be quite a print, it showed promise as an oxidizing agent. toxic, but they are used in minuscule quantities; He named it NaZ3 because the sodium form is used rather than the potassium as with traditional 4. platinum salts. Although not amenable to platinum For making your own ferric oxalate, 30% hydrogen peroxide H202 is used. It is highly reactive in concentrated form. Do not use it. Purchase ferric oxalate already formulated from a platinum supplier. Hydrogen peroside is also used at 3% concentrations for contrast 3. The chemically correct term for this compound is sodium control. At this concentration, it is quite safe. Buy it premised from the hexachloroplatinate IV. Perhaps a better abbreviation would be Pt IV. pharmacy. 32 THE PROCESS

consequently, absorption of significant quantities sensitometry, use 0.66 g for a 1.2% solution (BS ferric through any route is unlikely. The salts can also be oxalate No. 2 Pd). If you want to take advantage of the purchased premixed, but their shelf life is limited. longer printing scale, as I do, use the 0.6% solution (BS In powdered form, they last indefinitely. ferric oxalate No. 2 Pt).

Solution A: ferric oxalate 27% THE RESTRAINERS(OXIDIZERS) (MSDS 3.4) Ferric oxalate 15 g Oxalic acid‘ 1g Water at 150 F 55 ml POIASSIUMCHLORAIE KC LO^

POTASSIUM DICHROMATE K2CR7O7 Continuous mixing and heating may be required. SODIUM DICHROMATE NA2CR7O7

In a ferric oxalate solution, there are always some SODIUM CHLOROPLAIINATE (NA2PICLb) molecules of ferrous oxalate present. In “fresh” ferric oxalate, the ferrous portion is minimal; nonetheless, The restrainers are powerful oxidizing agents used even infinitesimal amounts can reduce an equal amount for contrast control in the coating material or of metal salt to create “fog.” (See Chapter 11: developer. They are highly toxic by ingestion or Problems.) This can usually be controlled by adding a inhalation. Under certain conditions, they can be trace of oxidizer. With age, however, the ferrous oxalate extremely reactive and explosive. They are used in increases to the point that the solution should be minute quantities and are highly diluted in the Ptl discarded. Pd process (0.6 to 1.2%). It is advisable to purchase restrainers in premixed liquid form or to To test for the presence of ferrous ions use the have the powder quantities preweighed and placed following procedure (Photographer’s Formulary). in gelatin capsules by a lab utilizing a ventilation Place two crystals of potassium ferricyanide in a hood. Restrainers are a human carcinogen. They test tube with 2 ml of distilled water. Stir until caii be fiital if inhaled. dissolved. In the darkroom under a red light, add one drop of the ferric oxalate solution. Hold it up to the red light in such a way that you can see through it. If THE METALSALTS (MSDS 2.3) there are no excess ferrous ions, you will observe only a slight darkening. If excess ferrous ions are present, POIASSIUMCHLOROPLATINIIE 20% K2P~C~4 the test mixture will turn very dark or black. Step out of the darkroom and quickly look at the test container. SODIUMTEIRACHLOROPALLADAIE I 5% NA~PDCL~

The solution should appear yellowish-brown to orange. PALLADIUM CHLORIDE PDcL2 If a trace of ferrous oxalate is present, it will look green. When more ferrous ions are present, the color Platinum and palladium are salts used in con- goes to blue; the deeper the blue, the poorer the quality junction with a sensitizer for coating. Use the same of ferric oxalate. precautions as listed with the sensitizers. When drying in heated air, avoid close contact. Note Solution B: ferric oxalate with 0.6% restrainer the recommended commercial print dryers in (oxidizer) Chapter 2: Setting Up a Laboratory, or see the Solution A 55 nil drying apparatus in Chapter 10: Advanced Potassium chlorate (KC103) 0.33 g (will need Technique. custom scaling) Solution C This formula makes 0.6% potassium chlorate. It is used for Pt/Pd printing. Pure palladium has a longer To make 20% potassium chloroplatinite, mix: ‘ exposure scale. If you want to simulate the PdPd Distilled water at 100‘ F 50 ml Potassium chloroplatinite powder 10 g

’.I use 2 g of oxalic acid per 55 ml. When mixing ferric oxalate from powder, the extra oxalic acid facilitates getting the powder into ’. Technically, this is not a 20% solution; however, it has been listed as solution. Also, it decreases printing time. (Be careful of fog.) such in the literature for over 100 years-and it works. Or.. . AMMONIUMCITRATE (NH4)2HC6H507 (MSDS I) To make 15% tetrachloropalladate, mix: SODIUMCITRAIE C6H5N~3.2H20 Distilled water at 100“ F 55 ml Palladium chloride 5g Since relatively large amounts (1 to 3 liters) are Sodium chloride 3.5 g used, take precautions regarding skin contact and inhalation. Use in well-ventilated areas. A stan- Both platinum and palladium salts are mixed to dard surgical mask will not prevent inhalation of a near-saturated solution. Prior to their use, do not stir vapors from exposed liquid form. or shake the solution, as particulate metal may be transferred to the image. Potassium oxalate Potassium oxalate 66 g Distilled water at 120” F 200 ml Or.. . Potassium oxalate 454 g (1 Ib) THE USEOF METALUTENSILS Distilled water at 120 F 1350 ml It is difficult to determine when and where the caveat that metal shall not be in contact with platinum Developer is never discarded. The developer that materials started. The type of metal is not specified; is absorbed by the paper or evaporated is simply nonetheless, the same adage is repeated in much of replaced with fresh developer solution. As with sherry, the platinum literature. It undoubtedly refers to the a portion of the original mixture, no matter how old, potential for iron and platinum metals to go into remains. Paul Anderson used “30-year-old’’ developer. solution and plate onto one another. My developer’s age is over 20 years. To account for Today, most good laboratory equipment is made of water lost due to evaporation, occasionally add distilled stainless steel, a substance considered essentially inert water when crystallization appears. This may also help for many photographic processes. With high-quality to prevent streaking of black tones into highlight areas. stainless steel, if any metallic elements were to escape the (See Chapter 11: Problems.) bounds of your utensils, they would be in such infinitesimal amounts as to be insignificant. I have Ammonium citrate used the same stainless steel beaker and brushes with (Available in solution from BS) metal ferules for 20 years. I suspect that they are well Ammonium citrate 250 g plated with platinum and palladium. I would not, Water at 15‘ C 100 ml however, push the phenomena by developing prints in Make syrupy, add to 900 ml water stainless steel trays. I use plastic trays or those of baked Sullivan’s cold bath developer enamel. (Available as solution) Potassium oxalate 150 g Potassium monobasic phosphate 75 mg Water to make 1 liter DEVELOPERS(MSDS 1 ~2) Sodium citrate, potassium sodium tartrate, and FORMULAS sodium acetate are also used as developers (Nadeau, 1994). POTASSIUMOXALATE K2C202(MSDS 2.3) Potassium oxalate is mixed from powder to 35% An interesting observation is that image color is solution. In some literature, its use has been influenced by the content of metallic ions in the discouraged because of toxicity; however, with developer. If, for example, a Pt/Pd print is made following normal precautioiis, it presents no inore hazards a previous session of palladium printing, the image color than the inore-benign developers. This chemical will be slightly warmer. The reverse is true going from occurs naturally in leafy green vegetables, partic- platinum to palladium. Some may object to this. I find it ularly spinach. However, decomposition products desirable. Pt/Pd is a printmaking process. I limit my work of carbon monoxide and carbon dioxide may be to editions of SO. Each print is identified and distinct. I formed. Use only in a well-ventilated area. Skin would not prefer the mechanical perfection obtained by contact should be kept to a minimum. some other photographic processes. 34 THE PROCESS

THE PH printing speeds and a slight loss of contrast. The reverse is true for developers used at room temperature. Image The pH is defined in simple terms as the acidity or color can be greatly modified by developer temperature alkalinity of a solution. The pH progresses from the (see Chapter 10: Advanced Technique). Care should be most acid (1)to a neutral (7).Alkalinity is expressed to taken with extreme temperatures. Cold developer may the extreme of 14. result in granularity. Hot developer (over 120" F) can affect the internal sizing of some papers and produce PH 1 PH 7 PH 14 mottling of tones. Acidic -Neutral -Alkaline CLEARINGAGENTS Each whole number change represents an increase or decrease of a factor of 10. The issue of pH cannot be Clearing agents release and dissolve the remaining iron ignored, as many reactions in the Pt/Pd process salts from the paper. Failure to adequately clear paper are altered by changes in pH. It is recommended that results in a yellowish stain in white areas. This pH 0-14 paper strips be used to monitor and record the represents contamination and will shorten the archival pH of solutions. life of the print. See the section on fog versus stain in Chapter 11: Problems. '~t It is possible that, with an alkaline developer, insoluble crystals of iron hydroxide may form to participate on the paper. For that reason, it is wise to CHOOSINGA CLEARING AGENT monitor the pH of the developer, particularly if stains Choosing a clearing agent is best done by testing with a are found on the print following clearing. Citric or step tablet (see Chapter 8: Calibration). Pay particular oxalic acid can be occasionally added to bring the attention to the clearing action with coating that developer to a slightly acidic state. For those who use an contains little or no restrainer; it is the last to clear. acidic alum-rosin-sized paper, the internal paper sizing Palladium is more difficult to clear. Use only enough in the developer usually keeps it at a pH of 6.5. concentration and time to allow the whites produced by the step tablet to match the uncoated paper white. Too much of either may cause bleaching of the image, FILTERINGOF DEVELOPER particularly with pure palladium. Eventually, if developer is reused, crystals and undis- solved debris can form in the solution. If the developer is ETHYLENEDIAMINE ACID AND THE stored for a period in a glass jug, particularly at cooler TETRAACETIC temperatures, large crystals may form that cannot be SULFITES(MSDS 1 ) removed through the opening. As developer is close to a saturated solution, this is to be expected. It is not EDTA in a 3 to 8% solution is a chelating agent significant. Try heating and agitation. Eventually, pour used for developing and clearing. It is found in off the liquid into a new container. The sludge can now some foods. Contact with powder to eyes or be dissolved in a weak acid (clearing bath) and dis- inhalation can he harmful. Ingestion of large carded. Some PtPd printmakers occasionally filter the quantities can he harmful. developer before use. In that case, a coarse coffee Sodium sulfite (Na2S0,) is the active ingredient in filter can be used. Instead of filtering, I simply carefully hypo clearing agent. It should be mixed to a 20% decant at the first print of the day and throw out the solution with water. Avoid skin contact with sludge. powder. When clearing with the EDTMsulfite agents, the print should be rinsed in a bath of warm running water TEMPERATUREOF DEVELOPER before clearing. After that, the procedure for any of the The early literature refers to a heated developer. I have clearing agents is similar, requiring three baths of found that with potassium oxalate a temperature of 5 minutes each with intermittent rinses. When the first 90" F results in a quick reduction of the image with a bath becomes cloudy (after not more than two or three pleasing tone. Regardless of the temperature selected, it prints), discard, mix fresh agent, and move to the third should be consistent; higher temperatures result in faster position. THE DILUTEACIDS (MSDS 243) caustic. It burns skin, eyes, and clothing. When fumes are inhaled, it damages the cilia of the The acidic clearing baths are composed of highly respiratory tract and the covering of the bronchi- diluted acids. All are hazardous in concentrated oles in the lungs. It will also corrode the stainless form and should be handled carefully. However, steel in your darkroom. 1 do not use it. Never- if proper precautions are taken with the acids, theless, some professional printers with consider- the differences are largely academic. Even able experience in handling toxic chemicals use a hydrochloric acid, once mixed to its 1 % concen- dilute solution of HC1 as part of the clearing tration, is relatively safe. process with heavy, loosely woven papers. See Phosphoric acid (H3PO~)~comesin a 75% solu- Appendix G: Elements of Platinum Printing. tion. Take reasonable care. Add acid to water and protect eyes when mixing. If some acid gets in WARNING: contact with skin or clothing, immediately rinse. Seventy-five percent phosphoric acid solution will In mixing any dilute acidic clearing agent, always add not burn unless held against skin for an extended acid slowly to water. Protect skin and eyes. Adding period. The 2 to 4% solution used for clearing is water to acid may cause a splattering of concentrated safe unless carelessly used. acid when it comes into contact with water (as adding a Oxalic acid (C2H204)is mixed from powder to drop of water to hot grease does). a 1 % solution for clearing. It is also used in minute amounts in ferric oxalate sensitizer. The powder is FORMULAS relatively safe unless it is allowed to contact the skin or is inhaled. In solution, it is dilute enough to EDTA 8%' be harmless unless carelessly used. Do not splash EDTA 1 tablespoon (30 g) on skin or clothing. Water 750 ml Citric acid (H3C6Hg07.HZO) is a powder that is mixed in dilute form for clearing and develop- Our (the author and Keith Schreiber's) research has ing. It is found in citrus fruits. shown that EDTA alone does not work well with potassium oxalate developer with some papers, particu- HYDROCHLORIC OR MURIATIC ACID (MSDS 4) larly with palladium prints. However, if sodium sulfite is Hydrochloric (muriatic)acid (HC1) is mentioned in added, it is quite satisfactory for most papers. historic and contemporary literature and is still used by many as a clearing agent. It is extremely EDTA 8% with sodium sulfite EDTA 1 tablespoon (30 g) Sodium sulfite 1.5 tablespoon (25 g) Water 1 liter TABLE 4.1 RELATIVEEfflClENCV (Jf C~EARINI,AqENr5 Tk15 pRUptRTV VARIES WlTk CkOlLE Of PAPER ANd dELtLOPtR Hypo clearing agent Weakest 11 EDTA 8% Normally, if a clearing agent is to remove the iron salts, it must be acidic. However, because of EDTA 8% with sodium sulfite Hypo clearing agent the chelating properties of EDTA, the EDTNsulfite Citric acid 1% solutions can be effective while remaining in an alkaline Phosphoric acid 2% state. Hypo clearing agents contain sodium metabisulfite Oxalic acid 1% to produce acidity. For this reason, they may be Strongest U Hydrochloric acid 0.5-1 % more effective with some papers. With papers resistant to clearing, add 1 tablespoon of EDTA per liter of hypo clearing agent. Use with care, as it may bleach a pure palladium image. '. Using phosphoric acid and hypo clearing agent (sodium sulfite) in the same sink or drain may release sulfurous acid and caustic sulfur dioxide gas. The noxious odor is quite unmistakable, as the eyes water '. EDTA is normally supplied in the tetrasodium form. Some workers and the bronchioles contract. Evacuate the lab until the air clears; then, have found that alternating it with the disodium form helps to prevent run water into the sink and drain. black streaking. (See Chapter 11: Problems.) 36 THE PROCESS

Follow directions to mix Kodak Hypo Clearing using an acid-clearing bath, a final treatment in a Agent from powder to stock solution. Dilute stock buffering solution will give the finished print a quite solution 1:4.9 respectable pH of 6.5.

Or you can mix stock solution from chemicals: BUFFERINGSOLUTIONS Water at 125 F 750 nil SODIUM CARBONATE (NA~CO~)(MSDS 1) Sodium sulfite, anhydrous 200 g Sodium inetabisulfite 50 g SODIUM ACETATE (NACH~OO)(MSDS 1) Water to make 1 liter These are used as bufferirig agents arid are similar Phosphoric acid 2%” to household sodium bicarbonate. Phosphoric acid (75%) 24 ml Sodium carbonate 3% 30 g Water 1 liter Water to make 1 liter Or.. . Oxalic acid 1% Sodium acetate 1% 10 g Oxalic acid 10 g Water to make 1 liter Water 1 liter After clearing, soak the print, with agitation, for Oxalic acid is a fine alternative to phosphoric 3 to 5 minutes. acid. It does come in powder form, however, and may be difficult to get into and maintain in solution. While buffering may be a satisfactory solution, my If it crystallizes, it is hard to wash off the finished studies have further shown that using one of the print. nonacidic clearing baths may ensure a final print with an alkaline pH. It seems reasonable that if a nonacidic Citric acid (CGHsO,) bath will pass your tests, why not use it? If purchased in bulk form, the EDTA, sulfite, and hypo clear formulas Citric acid 30 g are no more expensive than acids. Water 1500 ml

Hydrochloric acid 1 % TONERS Water 1 qt Hydrochloric acid 37% 112 02 NEGATIVETONING FOR CONTRAST Use 1/2% with pure palladium. SELENIUM (MSDS 3) Avoid inhalation and skin contact. Use only in A MATTEROF PRINTPH well-ventilated area. While the print may be free of iron salts after clearing Selenium is a heavy metal used for negative toning and and washing, some acidic clearing agents may affect the is marketed as Rapid Selenium Toner, containing pH of the finished print. This is best checked by using sodium selinite, ammonium thiosulfate, and sodium a pH pen on the dried print. As the debate over sulfite. To increase negative contrast, it is used in a the necessity of “acid-free’’ platinum paper continues ratio of 1:3 with water (see Chapter 3: The Negative). (see Chapter 5: Paper), the photographer can take When direct-positive copy film is used to enlarge measures in the laboratory to raise the pH of the negatives, it is used at a ratio of 1:30 for archival finished print. My studies have shown that if you are permanence.

’. While EDTNsulfite solutions are quite effective clearing agents, they PRINTTONING are usually not adequate to clean brushes between coatings. (See Chapter 9: The Platinum and Palladium Print.) For this it is advisable Print color can be modified by a number of procedures, to have a small beaker of 2% phosphoric acid. including the combination of metals and the type and 10. A 4% solution may be needed to clear palladium salts. temperature of the developer (see Chapter 10: Advanced Technique). Nevertheless, particularly in the historic Gold chloride toning intensifies the image and gives it a literature, compounds containing gold, lead, mercury, cool, bluish tone. Gold chloride can be placed in the uranium, silver, pyrogallic acid, and copper are sensitizer, applied as a separate bath, or brushed on described for this purpose. through a film of glycerin (see Chapter 10: Advanced Technique).

GOLDCHLORIDE (MSDS 2) Gold chloride 5% 1g Distilled water 26 ml H(AuC14) Gold salt used for toning can be purchased as 1 % or 5% solution. Becmse of the For a separate bath, see Sullivan’s gold tone in the BS concerns expressed previously regarding lead arid catalogue. The formula is not presented here. It contains mercury, 1 consider gold to be the safest and most sodium formate and is more conveniently purchased efficacious of toiiiiig methods. premixed with instructions (Sullivan and Weese, 1998). 58 THE PROCESS

GLYCERINC,H5 (OH), (MSDS I) stores. Those that offer discounts for bulk chemicals, such as developers and clearing agents, are specified in Glycerin is an oily substance used for selective Sources. Shipping costs for acids in liquid form, such as development of platinum or palladium images. It phosphoric and hydrochloric acids, are high. If you live is harmless by any route and can be ingested. in a metropolitan area, buy these substances directly from a supplier. LEAD OXALATE (PB H204) (OXIDE) (MSDS 4) The coating agents used in Pt/Pd printing must be of This substance is extremely toxic by all routes. Use reagent quality. It is recommended that they be pur- with care, or do not use at all. It is used at 0.65% chased from specialty suppliers. At the time of publica- for toning. As a heavy metal, doses will accumu- tion, platinum salt was selling for about $20.00 a gram late in the body over repeated exposures. and palladium salt for $15.00 a gram. (In the standard mixtures as described in the chapter, given amounts of MERCURICCHLORIDE (HGCL~)(MSDS 4) palladium chloride will produce twice as much liquid WARNING: salts as platinum, so it is less expensive than platinum.) Mercuric chloride is extremely toxic by all routes and is Twenty-five ml of platinum salt costs $113.00 and 25 ml the most hazardous of chemicals used in the Pt/Pd of palladium salt costs $62.50. Each supplies enough to process. Use with care, or do not use at all. Avoid all make approximately 20 8 x 10 inch prints. contact. It is used as a 10% solution for toning. As a Arrangements have been made with two suppliers heavy metal, doses will accumulate in the body over (BS, PF; see Sources) to have a “Dick Arentz kit” repeated exposures. available, which contains the following items: 15 ml of 20% sodium chlotoplatinate (Na2) for SOURCESOF CHEMICALS contrast control From 1998, the time of the first edition of this text, to 25 ml palladium salt 2004, the World Wide Web has expanded to the point 25 ml each of sensitizers 1 and 2 Pt that all chemical suppliers have online catalogues. For Potassium oxalate developer that reason, and because prices fluctuate rapidly Sodium sulfite and EDTA clearing agents (particularly for platinum and palladium), a specific source list for chemicals is not provided. See Sources at This kit cost approximately $130.00 in 2004. With the end of this text for the various suppliers. Developing any kit, you should request platinum sensitizer #2 Pt and clearing agents need not be of high purity, so (0.6% potassium chlorate) instead of #2 Pd (1.2% industrial grades may be used. These can be found in potassium chlorate), which is normally supplied with chemical supply houses and at university chemistry palladium kits. Dick Areiitz and Keith Schreiber

39 40 THE PROCESS

Most artists’ papers are composed of relatively long, to be archivally sound and are used for commercial uniform fibers of plant cellulose. In Western countries, photographic paper. cotton and linen (flax) are the most common choices; Up to now, our studies have shown that, with some however, many other plant fibers can be utilized, exceptions, the best papers for the PtPd process have including hemp, jute, and gampi. Treated wood pulp tested acidic. Many most likely have alum rosin internal can also be used for good papers. In this case, the wood sizing. Prior to 1985, some of the best Platinotype pulp is processed so that only the high, alpha fibers papers were internally sized with an alum rosin material, remain. which made a slightly acidic (pH 4.5) paper. Combined For true rag paper, new cloth cuttings or “rags” are with a good external sizing of starch or gelatin, this used. Now, however, portions of the cotton plant left paper took a coating of PtPd salt and sensitizer (pH 1 to over from thread-making, called linters, are often 2) and maintained a creamy consistency that produced substituted. Linters of varying quality are available. the continuous tones desirable in some platinum prints The quality (and cost) of a paper is, in part, based on the (most noticeable in the areas of skies and flesh tones). amount of cotton or linen and/or the quality of the Then, around 3985, paper manufacturers began to linters used. follow the trend toward “acid-free” products. The Until the nineteenth century, all paper was hand- internal sizing was changed to an alkylketone dimer made. Today, although the process of hand-making product, sometimes with carbonates added. Many of paper continues and has hardly changed from its historic these “neutral” or alkaline papers, in our opinion, react processes, most contemporary papers are either mould- with the acid platinum coating to produce a typical acid- made or machinemade. Nevertheless, the handmade base reaction with precipitation that causes a reticula- process existed for centuries before mechanization and tion or “flocculation,” which produces granularity in is responsible for most of the principles of papermaking the image. The alkalinity also tends to neutralize the and its nomenclature (Hunter, 1974; Airey, 1996). ferric oxalate in the sensitizer. Handmade paper is still used by artists who demand Now, the situation has improved. Many papers the best papers available. Unfortunately, at this time, have regained usefulness for the Pt/Pd process due to only a few handmade papers may be adaptable for improved quality control and the adjustment of internal the platinum/palladium (Pt/Pd) printing process. Most sizing. Many papers that test alkaline, but otherwise have been replaced by mouldmade or machinemade have satisfactory characteristics, can be acidified prior to varieties. coating. (See Acidification, page 47.) Still, the platinum printer is in a bit of a quandary. While archival “permanence” is desirable, the sacrifice of image quality for permanence hardly justifies the use PLATI N OTYPE PAPERS of an unsatisfactory paper. For many, it is a tradeoff. When deliberating the choices we must make, it is When considering materials for purposes other than heartening to consider that the “acid-free” tenets are a those intended (see Chapter 11: Problems), finding recent concept, and many papers made centuries ago of suitable papers for platinum printing remains a con- good materials-and properly stored-remain in excel- tinuous challenge. While it may be fascinating to visit an lent condition. One must also consider that unlike artists’ supply store and examine the lovely texture and media, where the pigment or ink is laid onto the surface, patina of the finer papers, you must keep in mind that the PdPd process alters the chemistry of the paper few paper manufacturers intend that their products be significantly. Most likely, after processing an acid paper, immersed in chemicals and water for over an hour. much of the internal sizing, either acid or buffered, still Moreover, it hardly occurs to paper designers that less remains. However, most of the surface sizing has been than 1% of their purchasers will place an acid salt on removed. If a neutral or alkaline paper was used, the their papers to react unfavorably with the “acid-free” carbonate buffers, if present, may have been partially alkaline surface. dissolved. At the time of this publication, only one paper is If, after processing, an acid-free print is desired, made expressly for platinum printing: Arches Platine. certain procedures during the clearing cycle can be Fortunately, many other papers are adaptable for our followed. It is best to avoid acid clearing baths entirely. process. Most platinum printers prefer a 100% cotton Our testing of papers has shown that most cleared paper. Excellent papers are made from cotton linters. satisfactorily in hypo clearing agent, or in a bath of The treated alpha cellulose wood papers are considered ethylene diamine tetraacetic acid (EDTA) and sodium sulfite. For these, the pH after drying was alkaline. (See The choice of clearing agent is often dependent on Chapter 4: Chemicals.) the paper used. (See Chapter 4: Chemicals.) Most clear The proprietary “secrets” held by some paper satisfactorily in EDTNsodium sulfite solutions after an manufacturers have made the search for suitable initial bath in warm water. There may be some for papers even more perplexing. Our most recent tests which clearing is sluggish. Before going to an acid have indicated that other properties besides pH may clearing bath, it may wise to try a hypo clearing agent influence compatibility with platinum printing. Some with various concentrations of an EDTA additive. pH-neutral papers tested well; others did not. Those well into the alkaline range tested poorly. We suspect The time from coating to heat drying: that the presence of a calcium carbonate buffer inter- Each paper appears to have an optimum time during feres with the platinum coating material. Perhaps the which it should be allowed to air dry before subjecting it formation of the cellular fibers (the size and configura- to heated air. (See Chapter 9: The Platinum and tion of fibers) and the character of the surface Palladium Print and Chapter 10: Advanced Technique.) sizing are significant factors. Certainly more “dwell Platinum printers are versatile people and, in spite of time” in the sizing tub and pH adjustment of the the difficulties, they are producing exceptional prints surface sizing can be significant. As we continue to with the materials available. Each successful printer understand the characteristics of a good platinum paper, seems to have his or her own formula and paper. Many we may be able to identify papers that are both superb size their own paper, some double coat or acidify, and archival. experiment with temperature and humidity, manipulate the surface, and so on. Some do not work with PRACTICALMATTERS continuous tone images, so granularity is not noticeable. No doubt, considering the popularity of the PtRd As indicated, there are considerable variables involved in process, dozens of papers we have not tested are producing hand-coated photographic prints, many of presently being used to produce excellent platinum and which we cannot control. Most art papers are simply palladium prints. In the near future, other papers will be unsuitable and are best left for other processes. Double found by diligent Pt/Pd printers to be amenable to our coating or acidification in an oxalic acid solution can process. improve others. If the PdPd printer finds a suitable paper, slight changes in the manufacturing processes between lots can have serious ramifications on its continued use for SOME CHARACTERISTICSREQUIRED platinum printing. A change in pH, sizing, or any OF A PLATI N u M/ PALLAD I u M PAPER number of other factors from one batch to the next may render your favorite paper useless, or at least force you 1. A firm surface is required with enough “tooth” to to make changes in your printing methods. It is, hold the emulsion. The coating tends to slide off of therefore, advisable to record lot numbers on all paper slick or glossy papers. Choose a vellum’ surface. purchases. If a good paper is found, buy up what you 2. Permanence is required, usually 100% rag cotton. can. There is no assurance that the next run will be the 3. The paper must be adequately sized, internally and same. externally. Local climatic conditions and tap water chemistry 4. The paper must not be multi-plyed, unless you can also have significant effects on the printing plan to separate the sheets during processing. characteristics of different papers. A myriad of “per- (The two-plyed Rising Drawing Bristol may be an sonal variables” can also play a role in whether a exception. It has held up well under clearing and paper will work or not. Some papers work better with washing procedures.) brush coating, others with the rod. Some give equal 5. The paper must hold up after at least 30 minutes of results with both coating instruments. It has been found immersion in water. that many of the heavier papers and/or those with alkaline pH work better with acidification or double coating. With those papers, it may be more advan- tageous to first try acidification before using what may be an unnecessary second coat of ferric oxalate and ’. The term vellum should accurately be vellum-like. True vellum is metal salt. made from calfskin. 42 THE PROCESS

A WORDABOUT PAPER WEIGHT MEASUREMENTS 2. Papers that improved by acidification in oxalic acid (Table 5.2) The standard unit of measure for artists’ papers is gram 3. Papers that need double coating (Table 5.3) weight, or the weight of one square meter of the paper. Because the rapid changes and irregular manu- It is expressed in grams/meter2 or g/m2. It can also be of abbreviated as gsm. facturing techniques, by the time of publication, many of those listed may no longer be suitable, while others may Unfortunately, there is another standard using the English system of measurements, which is expressed as have entered the market or become modified to be of pounds/ream for the basis weight. A ream consists of value for this process. 500 sheets of paper. What size? The size is expressed as Other methods, such as Sullivan’s Ziatype or the basis size. To complicate matters, each type of paper has MaldeNare ammonium printing-out method, may have very different paper requirements. defined its own basis size: bond is 17 x 22 inches; text is 25 x 38 inches; cover (a common category for many platinum papers) is 20 x 26 inches. Therefore, a ream of TESTING TECHNIQUES Platinotype paper listed as 250 glm’ may exhibit a sticker on the package indicating that it is a 90-pound PH paper. Watercolor papers, many of which are listed Papers were tested prior to exposure utilizing the pH here, vary so much in size that they are mercifully listed marking pen marketed by Light Impressions. Based on as grams/meter’. indicator colors, papers were identified as at or below pH 6 (A, acid), at pH 7 (N, neutral), and at or over pH 8 (B, basic). SELECTEDPLATINOTYPE PAPERS AND THEIR CHARACTERISTICS STEP TABLET All papers were exposed with a Stouffer 4 x 5 inch step Dick Arentz and Keith Schreiber have continued the tablet. testing of papers following the first edition of Platinum 6 Palladium Printing in 2000. Suitable papers were COAlING SOLUlION placed in three categories: Papers were tested with a 50/50 mixture of platinum 1. Those that responded well to a single coat without a and palladium, and with 100% palladium, using a need for pre-treatment (Table 5.1) coating mixture of 50% metal salt and sensitizer, and

Paper Name PH Coating Tool Tone Quality Speed Index So UY ce

Arches Platine A/N brush or rod 9 1.0 DS, MA, NYC Bienfang Graphics 360 A brush 10 0.66 SS, NYC Bergger N brush or rod 10 1.o BS Crane’s Kid Finish N brush or rod 10 1.0 SS, BS Crane’s Platinotype A brush or rod 10 1.0 BS, NYC Fabriano Murillo A brush 8 1.0 G, DS, NYC Fabriano Perusia A brush 9 1.0 NYC, G Gampi A brush or rod 10 1.0 DS, NYC Lenox 100 (Parsons) A brush or rod 10 1.0 G, DS Masa, Smooth Side A brush 8 1.o G, DS, NYC Masa, Rough Side A brush 8 1.o G, DS, NYC Opaline A brush 10 1.0 NYC Rising Drawing Bristol A brush or rod 10 1.o DS Strathmore Series 500 Bristol A brush or rod 10 1.o NYC Van Gelder Simili Japon AIN brush or rod 9 1.0 BS, NYC

Abbreviations: A, alkaline; N, neutral. Paper Name PH Coating Tool Tone Quality Speed lndex Source

Arches Cover B brush or rod 9 1.0 DS, NYC Fabriano Artistico Extra White HP B brush or rod 9 1.5 DS, NYC Fabriano Classico CP B brush or rod 8 0.66 DS Fabriano New Artistico B brush or rod 9 1.0 DS, NYC Rising Gallery 100 B brush or rod 9 1.o DS Rives BFK B brush or rod 8 1.5 DS

Abbrevr&orzs: B, basic; CP, cold press; HP, hot press.

TABLE 5. 5 PAPERSfol? Dohk COATIN,

Pnper Name Couting Tool Tone Qunlity Speed Index Soiirce

Arches Cover B brush or rod 9 1.5 DS, NYC Arches Platine N brush or rod 10 1.5 DS, MA, NYC Fabriano Classico B brush 8 1.o DS Fabriano New Artistico B brush or rod 9 2.0 DS, NYC Fabriano Murillo B brush or rod 10 1.0 DS Rives BFK B brush or rod 8 1.5 DS Rising Gallery 100 B brush or rod 5 1.0 DS Twinrocker Watercolor N brush 9 2.0 DS, NYC Van Gelder Simili Japon, 225 gsm N brush or rod 9 2.0 BS, NYC, PT

Abbrezwtiorzs: B, basic; N, neutral.

1:1 solutions of A and B. (See Chapter 7: Choosing Your EXPOSURE Method.) Exposure was done with the NuArc 26K mercury vapor commercial printer.

SURFACTI N DEVELOPER After printing with the standard coating solution, each All test prints were developed in potassium oxalate at paper was tested with one drop of 10% Tween 20K,a 90' F. surfactant and spreading agent, per 2 ml of coating solution. For most papers, its use was either ineffective CLEARINGAGENTS or detrimental. With a few papers, the use of Tween 20R Papers were cleared in an EDTNsodium sulfite solution. improved the final result. It is mentioned specifically in (See Chapter 4: Chemicals.) Perma Wash and Ilford these paper's descriptions. Archival Wash Aid may also be effective.

COATING INSTRUMEN TS READING All papers were coated with a brush or a glass rod. In The smoothness of tone was assessed by visual inspec- general, the glass rod was best suited to the firmer tion. In all cases, pure palladium exceeded a Pt/Pd papers, which did not wrinkle at the first pass.' mixture in this category.' Crane's Crest Natural White Wove (Platinotype) was used as a standard and assigned DRYING the number 10. Other papers were assigned values from Papers were allowed to air dry 2 minutes before being 10 to 1. Those falling below 8 were subjected to acidifi- subjected to heated air. cation or double coating.

'. When using a glass rod with larger images (11 x 14 to 12 x lo), puddling may occur, making it difficult to maintain consistent passes. 1. Th'IS IS one of the many attributes of using palladium with the Some printers use a rod and then a brush to smooth out puddles. (See sodium chloroplatinatr (Na2) contrast control agent. (See Chapter 7: Chapter 9: The Platinum and Palladium Print.) Choosing Your Method.) 44 THEPROCESS

PLATE 5.2 BURNTTREES, MOC,OIIONRIM. AZ 5 x 7 iNrk PAllAdlUM PRINT ON FAbRlANO PtRLlSlA UNMASkLd EdGFS (krk SCkRElbtR) NOTESON SUITABLEPAPERS FOR THE PLATINUM/ PALLADIuM PROCESS Reflection densities were read using a Speedmaster PAPERSFOR SINGLECOATING T-85D. Maximum black (Dmax) and 90% of maxi- mum black (IDmax) were recorded. Exposure scales ARCHESPLATINE between papers were found to vary too little to be of Mouldmade in France of 100% cotton, Platine has a practical use. neutral pH, a hot-pressed surface, and a pure white color. Its weight is 310 gsm (grams per square meter). Sizes are PRINTING SPEED 30 x44 inches with four deckled edges and 22 x 30 All papers were assigned a Speed Index number to inches with two deckled and two torn edges. Martin indicate approximate printing speed compared to Axon worked with Arches to design this paper specifi- Platinotype, which was used as a standard with a cally for platinum printing. Double coating seems to be speed index of 1.0. A lower number, such as 0.66, beneficial; however, some printers have reported good indicates that the paper is 50% faster (or requiring 0.66 results with a single heavy coat on a well-humidified the printing time as a paper at 1.0). Higher speed sheet. The paper is surface sized on only one side. Coating indexes indicate a slower printing speed. (A 2.0 speed the wrong side will result in blotchy defects. If any coating index would require twice the printing time of the material at all is allowed onto the back side, it may creep standard of 1.0.) Usually the thinner papers (100 to into the paper and affect the surface sizing from beneath. 200 g/m2) had a faster printing speed than the thicker watercolor papers (200 to 300 g/m2). Also, the BIENFANG GRAPHICS 360 watercolor papers tended to be alkaline and responded A very thin U.S.-made 100% rag translucent marker best to acidification or double coating. Some are listed in paper, Bienfang is available in 50-sheet pads of 8 x 11 both Table 5.2 and 5.3 as being equally responsive to inches, 11 x 14 inches, 14 x 17 inches, and 19 x 24 either treatment. Treatment with oxalic acid tended to inches. It is machinemade, smooth, white, and slightly increase the printing speed of an individual paper, while acidic. Bienfang is a favorite of well-known platinum double coating slowed it. printer Lois Conner. It clears easily, but coating should best be done with a brush, since the paper quickly expands THE ACTUALPRINT and wrinkles as it absorbs the solution. Tonal quality While testing techniques may be interesting, a lot of the is excellent, but maximum density can be a bit weak.4 data simply does not translate when a platinum or palladium print is made from a camera negative. We

gave all papers this final assessment and incorporated 4. There are other tracing vellums such as Clearprint and Staedtler- our observations into our survey. Mars. They have qualities similar to Bienfang or Opaline/Opalux. BERGGERCOT 320 (BS). The pH is slightly acidic. This fine writing paper, This 100% cotton paper has a gum arabic surface sizing. found in many stationery stores, is often recommended Originally designed as the fiber base for Bergger’s silver as a good paper to start with in exploring Pfld and gelatin enlarging paper, this uncoated version is 320- other hand-coated photographic processes. It is very gsm weight (120-lb stock in U.S. measurements), with a easy to work with, but small watermarks scattered bright-white surface. It is thicker and more textured throughout each sheet, about 6 to 8 inches apart, can be than Crane’s Platinotype; however, it shares character- problematic when printing negatives larger than 5 x 7 istics such as Dmax, printing speed, and contrast. inches. Bergger COT 320 may require more effort in clearing (possibly requiring hypo clear with EDTA) and is fragile CRANE’SPLAIINOTYPE (NATURAL CRESI WOVE, ARTIFICIAL in the wash. Its pH is neutral, and there is no PARCHMENI,COVER) watermark. Machinemade in the United States of 100% cotton, Platinotype is available in brilliant white, creamy white CRANE’SKID FINISH (I use the creamy white), and Ecru 171 gsm, and 23 x 29 Machinemade in the U.S. of 100% cotton fiber, Crane’s inches with a smooth surface and cut edges. It is slightly Kid Finish is found as 32-pound white (AS81 11) or ecru acidic. Dick Arentz worked with Crane’s to design the (8116), as well as a variety of other shades and patterns. specifications for this paper, which replaced Crane’s The paper is 8 x 11 inches with cut edges. Larger sheets Artificial Parchment. This paper is the standard or (21 x 33 in) are available from Bostick and Sullivan baseline to which we compared all the others. It is 46 THE PROCESS marketed by BS as Platinotype, while the label on a LENOX factory-packaged ream reads Crest Natural White Lenox is machinemade in the United States from 100% Wove.’ Although both sides appear to be hot-pressed cotton by the Parsons Paper Company. (It may also before wetting, after the print has dried, one side has come from mills other than Parsons.) The Lenox from noticeably more texture than the other does. Daniel Smith is a slightly creamy white, 250-gsm sheet, which is available in 22 x 30 inch, 26 x 40 inch, and

‘b( 11 i All platinum and palladium prints reproduced in 38 x 50 inch sizes. It has four trimmed edges and a this text were made on Crane’s Platinotype unless slightly acidic pH. It has a fairly smooth surface, but a otherwise indicated. bit more tooth than Platinotype. It yields perhaps the smoothest tone quality of any paper tested.

FABRIANO MuRlLLo Mould-made in Italy of 25% cotton with 100% high MASA alpha cellulose, Fabriano Murillo is available as 360 Machinemade in Japan of 100% sulfite pulp, Masa is gsm, 27 x 39 inches or 19 x 27 inches. It has a rough bright white, 70 gsm, and available in 21 x 31 inch texture, cut edges, and is slightly acidic. It is available in sheets or 42 inch x 30 yard rolls. One side is smooth and cream from Daniel Smith or a range of 12 colors from the other is cold pressed. It has an acidic pH. Masa has a New York Central Art Supply. very soft surface and is prone to wrinkling when wet. It is best coated by brush. It clears easily, but has poor FABRlANO PERUSlA wet strength. Either side may be used, each having Handmade in Italy from 100% cotton, Perusia is a laid a distinctive look. Tween 20” helps to even out the sheet with a cold-pressed surface and distinctive griffin absorption. watermark. Its color is cream. The size is 19 x 26 inches, and the weight is 100 gsm. It has four deckled edges SWISS (OPALINE) PARCHMENT and a neutral pH. This is a paper of strong character, Machinemade in Switzerland of 100% sulfite, Opaline which can easily overwhelm an image. It must be comes in 22 x 28-inch sheets. It is 165 gsm and has an coated by brush due to the texture and needs about 50% acidic pH. It is a translucent paper with a very smooth more coating solution than normally used. It is slightly plate surface, making it difficult to apply a sufficient acidic. coating. The final print exhibits a delicacy that makes it unique from the other papers tested. CAMP1 (CAMPI TORINOKO) Handmade in Japan from 100% gampi fiber, Gampi has a pearlescent, satiny smooth surface. This 96 gsm, RlSlNG DRAWING BRlSrOL 20 x 30-inch sheet with four deckled edges is available Machinemade in the United States of 100% sulfite pulp, in white or cream. In the Daniel Smith catalog it is called Rising Drawing Bristol is white, single ply, 121 gsm, and Gampi, while New York Central calls it Gampi 22 x 30 inches with vellum or plate surface and cut Torinoko. Although described as “acid free,” our test edges; it has an acidic pH. It comes in two-, three-, or showed the pH to be slightly acidic. Gampi is four-ply for larger prints. The use of Tween 20’ another paper with a lot of character. Its long swirling improves the coating. The two ply generally does not fibers make tearing problematic. Drawing a bead separate during clearing and washing. (Source: DS) of water along the tear bar to soften the fibers makes it much easier. Coating can be done either by STRATHMORE500 BRlSrOL brush or rod, and a single coat yields excellent results. Machinemade in the United States of 100% cotton, This paper is rather expensive, however, at around Bristol Series 500 is white, 125 gsm (one ply), and $10.00 per sheet. A drop of Tween 20“ per 2 ml of comes in 23 x 29-inch and 30 x 40-inch sizes. It also coating solution will greatly improve coating smooth- comes in plate or vellum (kid) and has no deckles and ness and also increases Dmax. an acidic pH. Tween 20R may improve coating but lowers Dmax. This is a good, but undistinguished paper suitable for students and beginners. The multi- ’.We have noted some problems with the consistency of the Crest Natural White Wove paper runs. We will continue to work the Crane’s plyed varieties tend to separate in solution. (Note that Company; however, it is advisable that sample sheets be tested and the Strathmore 400 Bristol series is made of treated batch numbers recorded before ordering a large amount of this paper. wood pulp fiber.) VAN GELDER SlMlLl JAPON can be observed, indicating that a shorter “dwell time” Mouldmade in Holland of cotton and high alpha in the acid solution may be necessary. cellulose, Van Gelder Simili Japon is off-white and is If a step tablet print is compared to one made available at 130 gsm in 18 x 25-inch and 25 x 37-inch from untreated paper, relative speed changes can be sizes, and at 225 gsm in the 25 x 37-inch size. It has a observed. (See Chapter 8: Calibration.) It is generally smooth-wove surface with two deckled edges and an found that creating an acid surface accelerates the acidic-to-neutral pH. Simili Japon at 130 gsm can be inherent slower printing speed exhibited by many singled coated; however, the heavier 225 gsm improves heavier papers. with double coating. (See Papers for Double Coating, page 48.) It has also more contrast than most papers. The paper has a large fleur-de-lis watermark PAPERSAMENABLE TO ACIDIFICATION (a stylization of the initials VG) at the lower right, which can be a nuisance if you do not print with wide borders. ARCHESCOVER (Simili Japon is Schreiber’s favorite paper, but there have Mouldmade in France of 100% cotton rag, this paper been inconsistencies in paper quality.) A paper offered comes in white or buff and in sizes from 19.5 x 25.5 to by BS called Socorro Platinum is said to be a modified 40 x 60 inches. Weights from 250 to 300 gsm are version of Simili Japon without the watermark; one side available. There are two natural deckled edges and is smoother than the other. It comes in a sheet size of two torn edges. Judging from the many available sizes 23 x 29 inches. and weights, Arches Cover is one of the most popular rag papers in the catalogue. Arches Cover, as well as Rives BFK, were two of the many papers that went \<>I i A Note on Sources: Unlike chemicals, the cost of papers is fairly consistent among suppliers. Many papers to an alkaline state in 1986. PtPd printers sorely missed are available from many sources and are indicated with them. Now, with acidification techniques, they can once the code (G). Writing and drawing papers are found at again be used for our process. We tested the 270-gsm stationary stores (SS). For those papers available from weight and found the tonality, particularly with specific suppliers, the code is given for reference in pure palladium, to be exceptionally smooth. As Sources. with most of the heavier watercolor papers, it has an alkaline pH.

I D I F I CAT I N A c o FABRIANO ART/Sr/scO EXTRAWHITE (FORMERLYFABRIANO UNO) This paper is mouldmade in Italy of 100% cotton. A 1 to 2% oxalic acid solution can be used to acidify the It comes as both 300 and 600 gsm in a 22 x 30-inch paper surface and prevent the acid-base reaction size. It is very white with a special surface sizing commonly observed when an acid ferric oxalate solution that gives the hot press a light texture. Fabriano Uno (pH 1 to 2) reacts with an alkaline paper surface. The has long been the favorite of custom printer Stan oxalic acid can be applied by brush, rod, or by soaking Klimek and is quite amenable to humidification and the entire paper in the solution. The normal time double coating. (See Appendix G: Elements of allowed is 1 to 3 minutes, although this may vary Platinum and Palladium Printing.) This paper has an depending on the paper. Brush or rod coating may be alkaline pH. less destructive to the surface sizing of the paper. Usually, the brush is more effective for a larger paper size. The paper can be dried with heat or allowed to dry FABRlANO NEWARr/Sr/CO (FORMERLYFABRIANO ARTISJICO) naturally. Some papers, such a Fabriano Classico, may Handmade Fabriano papers are based on traditional require soaking. In this case, it is best to place the print Italian techniques, which can be traced to Renaissance overnight on a drying screen. Working with a particular artists. Artistico is mouldmade and has a distinctive paper will require some experimentation before attempt- watermark. Fabriano has made some changes in the cold ing to print a complete image. press (CP) version, calling it Artistico Extra White Soft A 4 x 5 step tablet is handy. As well as determining Press. The hot press (HP) version has remained the the smoothness of the tone, defects such as those that same. We tested the 140-gsm white HP, which is might interfere with the final coating can be detected. If a available in a 20 x 30 inch size. Surface acidification paper is soaked in oxalic acid, an optimum time can be was not as effective as soaking the paper. It has an established. If left too long, breakup of the surface sizing alkaline pH. 48 THE PROCESS

FABRIANOCLASSICO Other papers clearly benefited from double coating Classic0 is mouldmade of 50% cotton and 50% high and were worthy of inclusion in this text. alpha cellulose. It also has a distinctive watermark and comes in a 27.5 x 39-inch size with four deckled edges. FABRIANOMURILLO It has a hard surface with a distinctive texture. We tested Murillo is mouldmade of 25% cotton and sulfite. the 115-lb white CP. Soaking was the preferred method It is acid free and measures 27.5 x 39 inches. It is a of acidification for this alkaline paper. heavy, rough paper, possibly amenable only to certain imagery. It has a hard surface with a distinctive texture RIVESBFK and is available in many colors. We tested the 360-gsm Mouldmade in France of 100% cotton, Rives BFK is ivory. likely the most popular of printing papers. We tested the 250-gsm white in the 19.5 x 25.5-inch size. TWINROCKERWATERCOLOR This paper is handmade in Indiana of 100% cotton and RISINGGALLERY 100 cotton rag. It comes in white, 200 or 400 gsm, in a wide Machinemade in the United States of 100% cotton, range of sizes from 6 x 8 inch to 30 x 40 inch, hot- or Gallery 100 comes in white, weighing 245 gsm, and in cold-pressed, with four deckled edges that are either 23 x 29-inch and 26 x 40-inch vellum or plate finishes regular or an exaggerated “feather” deckle. It has a with cut edges. It has an alkaline pH. Gallery 100 has neutral pH. The use of Tween 20R improves both been a favorite of many printers. Acidification will coating and Dmax. smooth out what is normally a chalky, flocculated surface. TWINROCKERWHITE FEATHER WATERCOLOR DECKLE Like Gampi and Perusia, Twinrocker White Feather Watercolor Deckle is a paper with considerable char- PAPERSFOR DOUBLECOATING acter, primarily due to the exaggerated deckled As stated, double coating has been often used to allow edges. It is available in a wide range of sizes. Small the first coat of ferric oxalate to acidify an alkaline sizes, such as 6 x 8 inch and 9 x 12 inch, make it paper. For this reason, with the advent of acidification particularly useful for smaller prints using the entire techniques, it is recommended that oxalic acid first be sheet. (See Plate 10.6.) The surface can be susceptible to tried before double coating. Although it has been found abrasion, so brushing should be kept to a minimum. with some papers that double coating increases the Clearing should be done using hypo clearing agent with Dmax, this is not observed in all papers. In fact, the EDTA. second coat may partially dissolve the first, diluting and This paper should be coated by brush, using about muddying up the entire surface, with a decrease in 50% more solution than normal. With Twinrocker printing speed and Dmax. Even in the case of a good papers, printing times may be 50 to 100% longer. double coating, printing speed is usually slowed. Tween 20 gives much improved absorption and Dmax. Double coating techniques vary with many printers. Some dilute each coat, allowing them to dry naturally. VAN GELDERSIMILI JAPON Some speed dry. In our testing, we found that some The 225-gsm version of this paper is particularly papers previously discussed for acidification also may amenable to double coating. Two thin coats, the first improve with double coating. They are included in with a drop of Tween 20’”, consistently yield smoother, Table 5.3. richer prints. CHAPTER 6

PLATE 6.1 Rio dtl C~EITO.ITA~~ I996 I2 x LO iNCk Pd

49 50 THE PROCESS

If you have made some platinum or palladium prints, PAPER you may want to skip this section and go on to Chapters Purchase 25 sheets of 11 x 14 Platinotype from BS or 7,8, and 9. If you have not, now may be the time to cast PF, or get a pad or box of Crane’s Kid Finish from the theory aside for awhile and simply enjoy the thrill of stationary store. seeing-for the first time-a palladium print come immediately to life after contact with the developer. However imperfect it may be, do it! If you do not have UTENSILS an ultraviolet (W)light source, do it in the sun! 11 x 14 corrugated cardboard 4 oz. glass beaker containing distilled water and THE SUN PRINT dropper Blotter or fiberglass drying screen The sun was the first source of light for photographic printmaking. It is still the primary UV light used by Blow dryer many platinudpalladium (PdPd) photographers. Brush (Start with a 1-inch camel hair negative Complete supplies are not needed. Later on, you can dusting brush. The coating rod or Puddle PusherK supplement the basics as necessary. Review Chapter 2: will be discussed later in Chapter 9: The Platinum Setting Up a Laboratory regarding workspace. Scan and Palladium Print, under Coating Instruments.) Chapters 7, 8, and 9 for a general idea of procedure. See Clean blotter Table 9.1: Algorithm for Platinum and Palladium Clock-timer Printing for the basic procedures in the making of platinum and palladium prints. You can read these Cotton gloves chapters in more detail later. Five trays not previously used for silver Four 1-02 dropper bottles with identical droppers THE BASICS Plastic 1-02 medicine cups Plastic pushpins CHEMICALS Print washer Purchase a basic Arentz kit from Bostick and Sullivan Printing frame with a hinged back (Souyces: BS, (BS) or Photographer’s Formulary (PF). It should VCS) contain the following items: Scissors and drafting tape (not masking tape) Palladium salt, 25 ml Thermometer Contrast control agent: sodium chlotoplatinate (Na2), 15 ml of a 20% concentration NEGATIVE Two sensitizers:’ ferric oxalate with and without Go through your stack of negatives to find the one with restrainer the most contrast (the shadow density must be almost Developer: potassium oxalate transparent, but still show detail), or follow the Clearing agents: ethylene diamine tetraacetic acid instructions in Chapter 3: The Negative to produce one. (EDTA) and sodium sulfite (You can also use hypo clear.) PROCEDURE * For our first palladium print, we will use Na2 as a 1. Pick a sunny day; work between 12:OO a.m. and contrast control agent. The second, ferric oxalate #2 or B, contains chlorate oxidizer. This will not be used now, 3:OO p.m. Choose an indoor space with soft incandescent lighting as your “laboratory.” but it can be used later if you wish to experiment with the Ratio Method. (See Chapter 7: Choosing a Method.) ‘. At this stage, you can rely on the instructions that come with the kit, or you can read ahend in this text to get a better handle on the process. ’. With any kit, request platiizuri? sensitizer #2 Pt (0.6% potassium For the mixing of developing and clearing agents, you can find the chlorate) instead of #2 Pd (1.2% potassium chlorate), which is directions in Chapter 4: Chemicals. Check the illustrations in Chapters normally supplied with palladium kits. 8 and 9 for more information on coating. CkAPTER 6 Tkt Fins1 PRiNT 51

2. For the paper coating, work in proportions of 6 drops of ferric oxalate sensitizer (No. 1 or A without oxidizer) added to 6 drops of palladium salt. Depending on the size of the area to be coated, the total of 12 drops can be divided or multiplied as needed. If your first print is from a 4 x 5-in negative (or two 2 U4-h negatives), a total of 12 to 24 drops should do. If not sure, err on the side of too much rather than not enough coating. 3. Using the dropper, put the solution in a plastic medicine cup or shot glass. 4. Examine your negative. If it appears thin (if you are a silver printer, it most likely will be), add 2 drops of 20% Na2 to the total of 12 drops of sensitizer and palladium salt. If the negative has more contrast (grade 1 silver paper), use just one drop of 20% Na2. 5. Anchor the paper to a smooth surface with drafting tape. Lightly scribe the area to be coated with a hard pencil. Allow at least 1/2 inch beyond the negative on all sides. 6. Hold the brush in your working hand and use the other to pour the mixture onto the center of the area to be coated. Brush quickly to cover the image area completely. Make only two or three passes, then stop. Streaks may show; this is not of consequence (see Figures 9.1 to 9.8). 7. Tape the paper to corrugated cardboard. Using a hair dryer set at medium, position it 8 to 12 inches from the paper (see Figure 9.16). Dry by constantly moving the dryer. Dry the back side. The coating should take on an orange color. Do not burn; burning will show as a deep orange or rust color. Avoid breathing in the direct vicinity. Turn your FIGURE 6.2 EkposuRt IN ikt Sulu head to the side, or wear a mask. (See Chapter 2: Setting Up a Laboratory for suggested drying units.) 8. Clean the glass of the printing frame. Position the dull side of the negative on the coated paper, and the print. Most likely, you will see a printing-out orient it in the center of the glass so the hinge of the image of the shadows but nothing in the highlights. back will fall midway across the negative. Lock in Lock the frame, place it in the sun, and restart the position. You may want to include a small step timer. Repeat this process every minute until a tablet (see The Step Tablet in Chapter 8: barely discernible image appears in the highlight Calibration). Open one side of the back and peel area. Stop and record the time. back the paper to check that the negative does not 10. In the wet area of your lab, divide the clearing shift. If there is a problem, the pressure can be agent into three trays. Fill one tray with room increased by the addition of felt between the paper temperature water. Position a clean, dry tray at and back. one end. Work in soft incandescent light, such as a 9. Lock the holder and place it in the sun (Figure 6.2). 40-watt bulb placed 4 feet from the trays. Pour the Set a timer. After 3 minutes, stop the timer, move to developer into a beaker. For now, use it at room a shady area, unlock one half of the frame, and peel temperature. Put the print face up in the dry tray. back the paper (Figure 6.3). For assessment, Prepare yourself (and any companion) for one of concentrate on the highlight and shadow areas of the profound joys of photography.

51 52 THE PROCESS

agitation for 5 minutes each in the other two trays. The paper will become quite fragile at this time; it is probably wise not to use print tongs. The print will bleach slightly, but don’t worry. There will be considerable dry down. 12. Wash the print for 15 minutes in rapidly changing water. Avoid direct contact with the water stream, as it may punch a hole in the print. Place the print face up to dry on a blotter or drying screen.

ASSESSMENTOF THE PRIN~

If the negative is somewhat within the range of the paper coating, the print may be quite satisfactory. Using the basic controls of contrast control and printing FIGURE 6.3 CkEckiNC, EXPOSURE time, the image can be fine-tuned to display many of the unique characteristics of the palladium print. Test strips can be made, printing only a portion of the negative. 11. Refer to Figures 9.8 through 9.20 in Chapter 9: (For drying with the hair dryer, pin them to the The Platinum and Palladium Print. Quickly pour corrugated cardboard.) It is likely that many platinum the entire amount of developer (at least 1 liter) printers work with this trial-and-error method, gaining onto the print. The full image will appear intuitive experience with time. immediately. Set the timer for 2 minutes and As appealing as printing by intuition may be, for agitate. When the timer goes off, carefully remove many the time comes when more controls are needed for the print from the de~eloper,~slowly rock it for this costly process, particularly in the duplication of about 30 seconds in the tray of water, and then prints and the management of problematic negatives. As place it into the first of the clearing trays. Agitate with a myriad of endeavors, mastery is based on the for 5 minutes. Keep the print face up. Repeat this understanding and practice of technique.

Do not discard the developer. As you will discover, it is reused and brought to the original volume by adding more fresh developer. CHAPTER 7 CHOOSEYourz METHOD

53 54 THE PROCESS

Three of the commonly used methods of contrast control METHODSOF CONTRAST CONTROL for platinum and palladium printing are covered in this chapter. Each uses a different oxidizer to “restrain” the 1. The Ratio Method (formerly the A + B Method) reduction of platinum or palladium metal salts to their 2. Sodium chloroplatinate (Na2 Method) elemental form. For a more complete discussion, see a. The Serial Dilution Method Appendix A: The Chemistry of Developing, Contrast i. Using droppers Control, and Clearing Processes. ii. Using pipettes In the planning of a platinudpalladium print, one b. Percentage Method of the first steps should be the selection of the metal or 3. The Dichromate Method combination of metals. (See Chapter 9: The Platinum and Palladium Print, Table 9.1: The Algorithm.) For the i, 4 :! i . The ammonium-based processes, the Ziatype and beginner, this choice will most likely be arbitrary; the MaldeWare Methods, as outlined in the Platinum however, for the more advanced worker, the choice & Palladium Printing, 1st edition, are unique and not will depend on the previsualization of the final image amenable to the contrast control methods as presented and examination of the negative. The type of paper to be in this 2nd edition. It is my opinion that with the advent used will also become a factor in this decision. of Na2 and controlled humidification (see Chapter 10: Following these choices, a method of contrast control Advanced Technique, and Appendix G: Elements of must be decided upon. Here the options become some- Platinum and Palladium Printing), the ammonium-based what interdependent. Not all contrast control methods processes are somewhat divorced from the advances in are amenable to particular metal combinations. For the more traditional methods. If interested in the example, all of the methods described here will work with ammonium based process, the reader is referred to the pure palladium; however, if one wishes to combine excellent sources: palladium with platinum, the Na2 Method is not an option. For the MaldeIWare Method: http://mikeware.demon. The negative and type of project are important in co.uk making these decisions. If the’negative is less contrasty For the Ziatype’ : http://www.bostick-su1livan.com than optimum, Na2 may very well work the best of the Sullivan and Weese: The New Platinum Print 1998 following options, as its oxidation properties do not cause the excessive flocculation seen with the other methods (see Chapter 4: Chemicals). If the job is going THE RATIOMETHOD to involve numerous prints, without the time to care for The Ratio Method uses two solutions of ferric oxalate each image, the dichromate method has the advantage sensitizer, the first (A) is 27% ferric oxalate. The second that all of the papers can be coated at once with the (B) also is 27% ferric oxalate, but it also contains the same coating ingredients. Furthermore, if you want the oxidizer potassium chlorate at either a 0.6 or 1.2% “platinum” look and the image is busy enough with no concentration. By altering the ratio of solutions A and B smooth tonal areas, by all means use Pt/Pd. Even with to make 12 drops total (or multiples thereof), ES can be the lowest paper exposure scale (ES) (No. 13) mixture, modified over a range of approximately f0.9.’ This the grain will not show. total of 12 drops is added to an equal amount of If the initial goal is to calibrate the light source and platinum, platinudpalladium, or palladium salts. visually observe the effects of the contrast control agents, The Ratio Method is the original and most versatile as will be described in the next chapter, either the Ratio of contrast control methods, and is the most commonly or the Na2 Methods are applicable. The steps in cali- used. The ability to titrate minuscule amounts of oxidizer brating a light source are presented for both methods in by using two solutions makes it the most accurate, Chapter 8: Calibration. particularly when printing long-scale negatives in which All of this may a bit daunting to the beginner or slight errors in the contrast control ingredient can distort hobbyist. However, if one becomes immersed in the Pt/ the refinements needed for the final presentation. Pd process, as many do, much of the information This method’s chief disadvantage lies in the property presented here will begin to make more sense. Most of chlorates, in sufficient amounts, to cause flocculation will find themselves coming back to particular sections of this book, sometimes years later, to review their readings and put theory into the act of obtaining solid For an introduction to the basic sensitometry as related to negatives, results. see Chapter 3: The Negative. ChAprER 7 CkoosE YOURMEThod 55 by acting unevenly on the paper fibers. (See Chapter 4: Chemicals.) This effect is observed in smooth areas of the print as “grain” and is proportional to the concentration of the chlorate in the coating mixture. When using Mixture Negative Contrast Solution Drops negatives of great density range (DR) (2.0 to 1.7), the effect is hardly noticeable. With negatives of DR 1.65 to No. 1 Very Contrasty” A 12 1.1, however, the grain is increasingly severe to the point B 0 Pt/Pd PlatinudPalladium 6 Pt/6 Pd 12 where the smooth tones of sky or flesh, when printed with (1.8) a negative of DR 1.1, are notably degraded. Pd Palladium (2.1) 12 Pd 12

PLAlINUM OR PALLADIUM? No. 2 Very Contrasty A 11 B 1 The Ratio and Dichromate Methods are the only PdPd PlatinumPalladium 6 Pd6 Pd 12 processes that allow the use of platinum, either alone or (1.7) ~ in combination with palladium. With pure platinum, Pd Palladium (1.9) 12 Pd 12 some form of hydration or the use of glycerin is necessary No. 3 Contrasty A 10 to facilitate the reduction and precipitation of the B 2 platinum metal. (See Chapter 10: Advanced Technique.) PdPd PlatinudPalladium 6 Pd6 Pd 12 The use of various proportions of platinum and (1.6) ~~ palladium is still the combination of choice for many Pd Palladium (1.8) 12 Pd 12 printers. While most use the metals in 1:l combinations, No. 5 High Medium A 8 some vary the proportions. As time goes on, more and B 4 more printers are finding pure palladium to be an elegant PdPd Platinum/Palladium 6 Pt/6 Pd 12 and subtle means of expression. (1.5) Pure palladium can be used with all of the three Pd Palladium (1.7) 12 Pd 12 contrast control methods. When used with the Ratio or No. 7 Medium A 6 Dichromate Methods, it is quite amenable to high DR B 6 negatives (2.0 to 1.7). Unfortunately, with negatives of Pt/Pd PlatinumA’alladium 6 Pt/6 Pd 12 less contrast, the longer inherent scale of the palladium (1.4) print requires contrast mixtures containing significant Pd Palladium (1.6) 12 Pd 12 amounts of oxidizer. Here, the advent of sodium No. 9 Low Medium A 4 chloroplatinate has been a revelation. B 8 Pt/Pd PlatinudPalladium 6 Pt/6 Pd 12 (1.3) THE STANDARDCONTRAST RANGE CHART Pd Palladium (1.5) 12 Pd 12 If one were to run the calibration tests described in Chapter 8, a Standard Contrast Range Chart could be No. 11 Thin A 2 B 10 constructed for each method, which would match PdPd PlatinudPalladium 6 Pd6 Pd 12 negative DR to the ES of possible contrast mixtures. (1.2) After studying the various choices, the reader can decide Pd Palladium (1.4) 12 Pd 12 which method to use in calibrating his or her laboratory No. 13 Very Thin A 0 equipment. B 12 PtIPd PlatinumPalladium 6 Pd6 Pd 12 1.1 *:I After years of working and teaching in various (1.1) environments and using different light sources, I have Pd Palladium (1.35) 12 Pd 12 found that the negative DR charts presented here are uncannily accurate and are applicable to most situa- *Expect fog with the No. 1 mixture. Fogging should not occur with intermediate mixture No. 2. tions. If the calibrations described are done with care, it is highly likely that a chart will be constructed nearly For teaching purposes, the DR of a No. 7 Pt/Pd identical to the one shown in Table 7.1. mixture has been changed from 1.352 to 1.40. About the standard negative contrast range chart ’. In Chapter 8: Calibration, it will be seen that the ES of a No. 7 Ferric oxalate with 0.6% restrainer was used with mixture is actually 1.35 (see Figure 8.7). For teaching purposes, 1.40 both Pt/Pd and palladium. will be substituted here. 56 THE PROCESS

The Pt/Pd mixture is 50% of each metallic salt and ADVANTAGES is presented in normal type. 1. The palladium ES can be decreased without the Equivalently numbered palladium mixtures are flocculation associated with the chlorates and directly below Pt/Pd and are presented in bold italic dichromates. type. 2. A single family of palladium curves can be used The numbers in the chart are divisible by two, throughout the typical ES normally displayed by Ptl making the use of small test strips more economical. Pd and palladium. Note that intermediate, even-numbered mixtures 3. The sepia palladium hue is maintained throughout may also be used in printing. the ES, only graying slightly at the higher concen- A No. 13+ mixture can be employed by using all trations of Na2.5 ferric oxalate B with 1.2% chlorate (BS No. 2 Pd). 4. All prints can be made with the less expensive The DR for PtPd will be 1.0. The DR for palladium palladium salt, rather than combining it with the will be approximately 1.2. more costly platinum. Using a brush, a total of 24 drops should be enough 5. Pure ferric oxalate is used with Na2. It has a longer for a 5 x 7 print. Use 48 drops for an 8 x 10 print. shelf life alone than when mixed with potassium With a coating rod and sufficient practice, 1/3 less chlorate in the Ratio (A+B) Method. material can be used. 6. Pure palladium prints have an inherently smoother tonal scale than that of PtPd prints. KO11 : Because of the accuracy and versatility of the Ratio Method, it will used as a basis for the seiisitometry DlSADVANlAGES discussed in Chapter 12: The Film and Paper Curves. 1. Na2 is so potent that exact concentrations are For the practical applicatioiis that follow in Chapter 13: necessary for predictable results. At the lower Using the Print Curues, both the Ratio and Na2 concentrations for longer scale prints, there is Methods will be presented. difficulty in obtaining a precise measurement with- out the use of a pipette. Our studies have tentatively shown that at the most dilute concentrations of SODIUMCHLOROPLATINATE' (NA~) Na2, even a pipette does not provide the accuracy of the traditional Ratio (A B) Method based on Richard Sullivan of Bostick and Sullivan (BS), while + 12-drop (or ml) proportions. This is most obvious perusing the historic literature, noted the mention of at the longer-scale palladium mixtures (ES 1.90' sodium chloroplatinate. Although not amenable to to 1.75). platiiaum or PtPd printing, it was found to be an 2. In the Serial Dilution Method (to be discussed), effective source of oxidation when using pure palladium. there are only eight practical standard contrast (See Appendix A: The Chemistry of Developing, Contrast ranges for Na2, compared to 17 available by Control, and Clearing Processes, for the chemical combining the families of PdPd and palladium reactions involving Na2.) curves using the A B Method. While this form of platinum salt is not suitable for + providing the platinum to make a print, it showed promise as an oxidizing agent. Sullivan named it LIMITATIONS because the sodium form is used rather than the 1. Our initial studies have shown that with a given potassium as with traditional platinum salts. developer, regardless of the oxidizer used, palladium There are distinct advantages, as well as some ES and printing speeds are essentially the same. disadvantages and limitations, in using sodium chlo- roplatinate for contrast control.

'. These tests were done with fresh potassium oxalate developer. With used developer, the print color may vary between PdPd and palladium hues hecause of the presence of molecules residual from previous print '. Much of this discussion is derived from Contrast Contra[ for Iron processing. Cooler hues, similar to those of the traditional Pt/Pd print, Bmed Printing Processes by Howard F. Efiier (2001). It is presented can also be obtained with the use of ammonium citrate developer. with his kind permission. '. It fog is kept under control, an ES of up to 2.10 can be achieved 4. The chemically correct term for this compound is sodium with the use of palladium and sensitizers without oxidizers (the No. 1 hexachloroplatinate IV. Perhaps a better abbreviation would be Pt 1V. Ratio Method contrast mixture). With all oxidizers, ES less than 1.10 to 1.0 are THE SER14L DILUTION METHOD’ generally not possible. With increased concentra- USINC,D~oppt RS tions beyond that point, a Gamma Infinity occurs, Droppers may be the most practical measurement tools simply slowing printing speed without changes in for the student or casual palladium printer. Droppers contrast. should be of the same manufacture. This is generally The shapes of individual curves for each within our tolerances. To check, simply measure the contrast mixture are the same for Na2, chlo- number of drops per ml of each dropper. It will usually rate, and dichromate. In going from long-scale be 12 to 18. For the more advanced worker, pipettes to short-scale prints, the toe of the curve is offer more accurate controls. uniformly shortened. (See Chapter 13: Using the To use serial dilutions of palladium salt using Print Curves.) droppers, ferric oxalate, and Na2, various dilutions of Printing speeds of individual curves for each the oxidizer must be prepared. Sodium chloroplatinate is contrast mixture are approximately the same. 7 usually supplied as a 20% concentration. For effective Shadow separation of individual curves for each use, a portion should be diluted by 50% with distilled contrast mixture is the same for Na2, chlorate, and water to make a 10% concentration. This in turn is dichromate. diluted again by 50% to make a 5% mixture. In some The property of minimizing grain in shorter-scale prints cases, this can be diluted once more to reach 2.5%. makes Na2 one of the major improvements in palladium Using data entered into the Plotter Program’, a printing. The simplification of using just one less costly standard contrast range chart can be constructed (Table metal for all contrast grades is a great advantage. The 7.2). Because the 12-drop system is traditionally used in typically smoother tone of the pure palladium print is platinum and palladium printing, I have kept with that only marginally affected by the addition of significant format. Each supplement of Na2 is in addition to the 12 amounts of Na2. drops of coating (6 drops of palladium salt and 6 drops One of the disadvantages is that measuring propor- of ferric oxalate A). Note that ferric oxalate A contains tions of lower concentrations with the dropper method no chlorate. Na2 concentrations of 2.5%, 5%, lo%, is imprecise. However, with smaller prints and test and 20% are used. The 5% and 10% concentrations are strips, it still may be the most practical method. doubled in some cases to two drops per 12 to reach Nevertheless, when more accuracy is needed, a pipette intermediate contrast ranges. For the greatest contrast, (or syringe) is recommended. For larger prints, propor- 20% is doubled or tripled to two or three drops per 12 tions can be calculated for the pipette using only the drops of coating. 20% stock Na2. . In the standard contrast range charts, two numbering systems are introduced. For the traditional ThE Mqic Bullti? Ratio (A+B) Method, contrast grade numbers 1 through The basic reduction-oxidation reactions of palladium 13 are used. For Na2 serial dilutions, the contrast num- salts and ferric oxalate appear to be the same regardless bers 1 through 8 are followed with the s suffix: Is, 2s, of the oxidizer used. As such, Na2 is not the “magic 3s, etc. bullet” that many of us had initially hoped for. It is still a pretty good bullet, but its use still requires basic negative 10 I The Serial Dilution Method does not approach control as described in Chapter 3: The Negative. Despite the accuracy needed for precise control of chemical early promise, the palladium printer still needs a negative reactions. However, as previously stated, photography of at least a 1.10 DR unless it has been developed in is an inexact science. Most steps of the photographic pyrogallic acid. (See Appendix D: Pyro and Platinum process encounter an error rate of f10%. Serious Printing.) Also, as print shadow separation is consistent photographers are not interested in turning their dark- with all oxidizers (uniformly poor in the Zone 11-IV rooms into analytic labs. Nevertheless, steps should be range), sufficient shadow separation must be recorded in taken to minimize the compounding of errors. the negative by using proper exposure.

’. The use of ammonium citrate developer at room temperature will yield a printing time 1/2 stop slower than with potassium oxalate at 90F. This variation has also been observed using the more traditional ’. Keith Schreiber and other PdPd printers formulated the basics of the oxidizers: the chlorates and dichromates. Serial Dilution Method. 58 THE PROCESS

dispensed with a pipette (or a 1-ml syringe). For example, a unit of 12 may call for one unit of 20% Na2. Six ml of coating solution at a 12:l ratio would call for .5 ml of Na2. If, instead, a 10% solution is called for, simply pipette half the amount of the 20% solution No. 1s" Very Contrasty (1.85) A 6 (see Tables 7.4. and 7.5). Palladium Pd 6 Using two factors, the total amount of coating and Na2 (Sodium 2.5% 1 the concentration of Na2 needed, calculations can be Chloroplatinate) made for pipette volumes of 20% (Table 7.3). No. 2s Very Contrasty (1.75) A 6 Palladium Pd 6 PERCENTAGES Na2 5 Y" 1 Accurate percent figures are simply metric calculations No. 3s Contrasty (1.60) A 6 of W100. However, when adding to an existing volume, Palladium Pd 6 Na2 10% 1 the correct formula is 100 x weight of compound/total No. 4s High Medium (1.50) A 6 weight of solution. Palladium Pd 6 Considering the error rate in photography, using Na2 5 Yo 3 these more precise calculations with Na2 is unwieldy No. 5s Medium (1.40) A 6 and unnecessary. Rather than recalculate the total Palladium Pd 6 weight or volume of Na2 added, I use the term Plus Na2 20 Yo 1 Percent (+X%). Obviously, when adding one drop to No. 6s Low Medium (1.30) A 6 12, the total is 13. When 2 drops are added the total is Palladium Pd 6 14 and so on. Whatever the deviation from precise Na2 10% 3 chemical accuracy, it is reproducible. No. 7s Thin (1.20) A 6 Nevertheless, this may become a problem in Palladium Pd 6 Na2 20% 2 mixtures calling for dilute concentrations of Na2, as No. 8s Very Thin (1.25-1.10) A 6 more fluid is needed to introduce a miniscule amount of Palladium Pd 6 the oxidizer. Using a more concentrated solution of Na2 Na2 20% 3 will obviate some of the volume discrepancies found in the Serial Dilution Method. Table 7.4 shows the ES of *May need one drop of 3% hydrogen peroxide to prevent fogging. palladium papers plotted for dropdl2 and +Yo. The percentage figures across the top represent those of both 100% and 20% Na2 solutions. USING, TkE PIPETTE Standard Negative Contrast Ranges can also be One can match the proportions of coating material and presented for the Na2 Method using percent values Na2 by using a pipette. Note that the various dilutions (Table 7.5). For convenience, the percent figures have of Na2 that have been discussed can be used. For more been adjusted for a 20% solution of Na2. accuracy, simple calculations can be made to use only the 20% solution of Na2. In measuring milliliters, for a COMBINING THE RATIOAND NA2 METHODS proportion of 12:1, 12 ml of coating solution would call for 1 ml of Na2 of a particular concentration. Lesser The method I use combines the attributes of both the amounts can be calculated by using portions of 1 ml. Ratio and Na2 Methods while avoiding their disadvan- For larger prints, a graduated cylinder and pipette' tages. may be the best choice. The palladiudferric oxalate For the subtle controls required for palladium prints coating material can be measured in a graduated from long-scale negatives, much greater accuracy is cylinder, while the portions of ml(s) are more accurately possible with the Ratio Method because the extremely minute amounts of oxidizer needed can be controlled '. Graduated cylinders and pipettes can be purchased from any with precision. Because of the infinitesimal amounts of chemical supply house. (Source: TE) Generally, depending on the size chlorate in the coating material, flocculation is not a of the print, a 5- or 10-nil cylinder is adequate. It is recommended that problem. When examining the Ratio Method Stmdard a number of 1-ml pipettes be obtained, as they are fragile. A glass S-ml syringe can be attached to the pipette with a rubber catheter, Negative Coiztrast Raizge chart (see Table 7.1), one will facilitating the withdrawal of fractions of a milliliter of 20% Na2 note that for the longer ES of palladium (2.0 to 1.70), without it entering your mouth (Figure 7.1). ratios of 12A:OB to 10A:2B are used. Using the TABLE 7.3 VO~UMESOf NA2 PER MI Of COAliNG SO~uTiONBAsEd ON NEquivE DR

Coating 1.0 ml. .010 .015 .020 .025 .033 .040 .050 .065 .075 .085 .lo5 .125 .145 .165 .235 .335 1.5 ml. .015 .025 .030 .040 .050 .060 .080 .095 .110 .125 .155 .180 .220 .250 .350 500 2.0 ml. .020 .030 .040 .055 .066 .085 .lo5 .125 .145 .165 .210 .250 .290 .330 .466 .665 2.5 ml. .025 .040 .050 .070 .083 .lo5 .130 .155 .185 .210 .260 .315 .365 .415 583 A35 3.0ml. .030 .050 .060 .080 .lo0 .125 .155 .190 .220 .250 .310 .375 .430 300 .699 1.00 3.5 ml. .035 .055 .075 .095 .120 .145 .180 .220 .255 .290 .365 .440 510 580 .816 1.15 4.0 ml. .040 .060 .085 .110 .130 .165 .210 .250 .290 .330 .415 500 580 .665 .932 1.35 4.5 ml. .045 .070 .095 .120 .150 .185 .235 .280 .330 .375 .465 365 .650 .745 1.05 1.50 5.0ml. .050 .080 .lo5 .135 .165 .210 .260 .315 .365 .415 320 .625 .730 330 1.17 1.65 5.5 ml. .055 .085 .115 .150 .180 .230 .285 .345 .400 .455 370 .690 .800 .915 1.28 1.85 6.0 ml. .060 .095 .125 .160 .20 .250 .310 .375 .440 500 .620 .750 375 .995 1.40 2.00 Negative DR + 1.85 1.80 1.75 1.70 1.65 1.60 1.55 1.50 1.45 1.40 1.35 1.30 1.25 1.20 1.15 1.10

Volumes of the palladium/ferric oxalate coating material are listed from 1.O to 6.0 ml. For larger prints, the amounts can be multiplied. lhe volume of 20% Na2 needed is found by looking up the DR of the negative to be printed. These have been carried to the 0.005 levels. This provides greater accuracy than the photographic process allows; however, in the case of multiplication or division, any inaccuracies will not be compounded. For practical purposes, measurements to the nearest 0.05 are adequate. For smaller prints, more care should be taken in dispensing the Na2 solution.

laboratory equipment available to most photographers, this equates to virtually immeasurable amounts of chlorate. However, when ES of 1.70 or less are required, the amounts of chlorate used rapidly accelerate from the ratios 8A:4B to OA:12B. Also, note that with pure palladium, the shortest ES is limited to 1.30. In the past, for thin negatives between 1.25 and 1.10 ES, we had to resort to the PtEd metal combinations. If one were to examine the Standard Negative Contrast Range chart for Na2 (see Table 7.2), it can be seen that palladium exposure scales from 1.75 to 1.10 are easily accommodated, with the added advantage that there will be little or no flocculation from the extra oxidizer needed. Therefore, I propose that palladium prints can best be made by combining the attributes of the Ratio Method with the Na2 (serial) Method.

In the longer-scale palladium print (ES 2.00 to 1.70), where measurements of Na2 are most difficult, chlorate or dichromate (either in the sensitizer or developer) can be used more effec- tively with the assurance that the infinitesimal amounts used will not appreciably degrade the print. For shorter-scale palladium prints from negatives with less contrast (ES 1.65-1.10), the Na2 Serial 1 X2.5% 1X5% 1X10% 3X5% 1X20% 3X10% 2X20% 3X20% 4X20% Method numbers 3s to Ss, either by dropper or Note that the +% numbers across the top bar are for both 100% and pipette, can be used with minimal deterioration of 20% dilutions of Na2. image tone. 60 THEPROCESS

TABLE 7.5 sT4Nd~~dCONTRAST RANGES fm NA~CONCENTRATIONS AS 4 Plus PERCENTAGF,Adjusrtd foR ikt Ust of A 20% SolbTioN of Nn2

Mixture Negative Contrast Na2 Solution Voltrnze

No. Is" Very Contrasty (1.85) +.208% Na2 20% Na2 +1.04% No. 2s Very Contrasty (1.75) +.416% Na2 20% Na2 +2.08% No. 3s Contrasty (1.60) +.833% Na2 20% Na2 +4.16% No. 4s High Medium (1.50) +1.25% Na2 20% Na2 +6.25% No. 5s Medium (1.40) +1.66% Na2 20% Na2 +8.3% No. 6s Low Medium (1.30) +2.50% Na2 20% Na2 + 12.5% No. 7s Thin (1.20) +3.33% Na2 20% Na2 + 16.6% No. 8s Very Thin (1.15 to 1.10) +5.0% Na2 20% Na2 +25%

"May need hydrogen peroxide to prevent fogging.

Drops of 50% sodium dichromate per 200 ml Negative Contrast for PtlPd of potassium oxalate

Very Contrasty 1 Platinudpalladium (1.SO) Palladium (1.95) Contrasty 2 Platinudpalladium (1.60) Palladium (1.85) High Medium 4 Platinudpalladium (130) Palladium (1.60) Medium 6 Platinudpalladium (1.40) Palladium (1.55) Low Medium 8 Platinudpalladium (1.30) Palladium (1.50) THE DICHROMATEMETHOD: CONTRAST CONTROL Thin 16 INGREDIENTIN THE DEVELOPER Platinurdpalladium (1.20) The following information is presented courtesy of Palladium (1.35) Very Thin 32 Phil Davis. Platinudpalladium (1.10) Palladium (1.25) PRINTINGWITH THE DICHROMATEMETHOD The main advantage of this technique is that all papers and test strips can be coated at the beginning of the printing session. Either PtPd or pure palladium can be used with this process. The disadvantages are as follows: (Table 7.6). At least 1000ml should be mixed for each, with the appropriate number of drops of sodium You will need a separate bottle of developer for each dichromate added to each 200-ml quantity. Very contrast range. shortly, you will have at least six developers. Only potassium oxalate developer can be used. With this method, you should mix the developer/ For my 12 x 20 prints, I use 3 liters of developer. restrainer combination as needed for the tests This method is, therefore, impractical for users of ChADTER 7 ChoosE YOURMEThod 61 ultra-large formats, unless you have the space and the A STANDARD checkbook for at least six 1-gallon jugs of potassium oxalate. In the earlier calibration procedures described in Platinum & Palladium Printing, 1st edition, a No. 7 con- trast mixture of the Pt/Pd Ratio Method using chlorate oxidizer was used as a standard. This has equal amounts STANDARDNEGATIVE CONTRAST RANGES: of ferric oxalate A, ferric oxalate B, and palladium and THE DICHROMATEMETHOD platinum salts. The ES is 1.40, in the middle of the possible ES (the equivalent of silver grade 2 paper). A standard negative contrast range chart for the When using Na2, this same ES is reached by using Dichromate Method can be similarly constructed one drop of 20% per 12 drops of coating. Any (Table 7.6). Note that the DR for appropriate negatives calculations, calibrating the light source, and working approximate those used with the Ratio and Na2 out printing speed can be based on this standard. The Methods. Although contrast may be increased by subsequent changes in contrast can be charted in both using a 64-drop solution, the extensive graining that number of drops and +%. For each, the mixture for results makes it impractical. calibration is 5s.

PLATE 7.2 BOG, T~OMAS,WV. 1989 1 2 x 20 Pd Thispageintentionallyleftblank CHAPTER 8 CALIBRATION

63 64 THE PROCESS

The main difficulty encountered in preparing this second CHOOSING A PRINT.TO.LIGHT DISTANCEWITH A POINT edition is that we are in a transitional period in the use LIGHT SOURCE of contrast control methods. The traditional Ratio Adjustment of most light sources will begin by choosing (A+B) Method was used entirely throughout the first an optimum light-to-print distance. The intensity of edition. It remains the method of choice for many light is a function of the square of the distance from the platinudpalladium printers. However, the advent of the light source. Therefore, a print placed 2 inches from Na2 method will prompt many printers to either the light source will receive four times the light as a abandon the Ratio Method or, better yet, become print placed 4 inches away. The same effect would be proficient in both. Furthermore, some teachers of this achieved between distances of 5 and 10 inches. A process favor one particular method and will instruct doubling of the distance decreases the light fourfold, accordingly, since both yield excellent results. while a halving of the distance increases the light To accommodate both methods, I will present the fourfold. following steps using the traditional Ratio Method using PdPd metals. Also, the equivalents using Nu2 will be (2x2)- 4 1 (5x5) - - 1 ~- 2s shown in italics. (4x4)-16=4 (~OXlo)-%%-?

CALIBRATINGTHE LIGHT SOURCE To calculate less-convenient proportions, use the same formula. For the difference between 6 and 9 The sun may be appealing as a source of ultraviolet inches, do the following: light; however, it is quite inconsistent. For the more (6 x 6) - 36 0.44 or 4 committed platinum printer, an indoor artificial light ~- - ~ source is a necessity. The various types available are (9 x 9) - 81 - 9 discussed in Chapter 2: Setting Up a Laboratory and Appendix F: Ultraviolet Light Sources for Platinum and Therefore, a print placed 9 inches would receive Palladium Printing. 4/9 or 44% the amount of light as a print placed at 6 For reproducible results, the intensity of effective inches. ultraviolet light should be standardized. With an “ideal” platinum or palladium negative and a coating of CHOOSINGA PRINT#TO.LIGHT DISTANCE WITH A materials mixed for medium contrast, the printing time FLUORESCENTTUBE BANK should be approximately 5 minutes. This amount of time is not long enough to be burdensome and still When determining a print-to-light distance for a bank of allows for burning and dodging procedures. fluorescent tubes, the calculations are not as simple as Specific types of light sources present other con- with a point light source. The mathematical formulas siderations. With a point source, such as a mercury vapor needed are beyond the scope of this text, and it is best to or metal halide bulb HID (high intensity discharge) use trial and error to determine the optimum distance. Luminaire, the print must be placed at a distance far Suffice to say that with a proper construction and UV enough to avoid noticeable vignetting at the corners. tubes, the ideal distance will lie somewhere in the With a bank of fluorescent tubes, since the intensity is previously mentioned 6-to-12-inch range. consistent throughout a reasonable range of light to print In practice, once this general concept is understood, distance, an ideal distance may be anywhere from 6 to 12 the light source can be optimized by experiments with a inches. There may be problems with the “scalloping” negative of known values: the step tablet. effect of uneven light from the tubes and the spaces between them. Increasing the distance to the print or THE STEPTABLET moving the printing frame occasionally during printing can solve this. This, and the ability to more easily dodge A step tablet is a manufactured negative with 21 steps or and burn using RubylithB material, is another reason for “wedges” of transmission densities. Starting at a designing the light box to radiate down from a horizontal transmission density of 0.05, each successive step position. increases by one half stop (0.15) (Table 8.1). Each step Following the determination of a time/distance is numbered, so by contact printing the negative, the factor, the contrast controls available with the combina- numbered transmission density can be matched to the tions of light, sensitizers, and paper can be analyzed. reflective density produced on the print. CkADTER 8 CAlibRAliON 6

Transmission step Transmission Step Density Density Nr.* NY. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 1 .05 11 1.55 I 2 .20 12 1.70 3 .35 13 1.85 4 SO 14 2.00 5 .65 15 2.15 6 .80 16 2.30 7 .95 17 2.45 21 1 8 1.10 18 2.60 20 2 9 1.25 19 2.75 10 1.40 20 2.90 19 3 21 3.05 18 4 17 5 "To avoid confusion regarding the mixture and step tablet numbers, I will use No. for contrast mixtures and the European abbreviation Nr. 16 6 for the step tablet number. 15 7

14 8

TRANSMISSION DENslriEs 13 9

Step tablets come calibrated or uncalibrated. The 12 10 calibrated version is more expensive and not generally 11 11 necessary. The uncalibrated versions are accurate enough for any use in normal photography. Simply assign the transmission densities listed to each numbered step (see Table 8.1). The range of transmission densities (the density range [DR]) of the step tablet far exceeds the reproduction capabilities of any photographic print material. A variety of step tablets are available: 0.5 x 5 inches (Figure 8.1) Kodak Photographic Step Tablet #2, uncalibrated and calibrated $25.00-$45.00 Stouffer T2115 $6.00 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 16 19 20 21 4 xS inches (Figure 8.2) FIGURE 8.3 Tkr PRlNTEd STEP TnblET SkOhlNq REfLEcTEd Stouffer TP 4 x5 $25.00 DENSlTlE5 (Sources: Photo Supply, VCS, GAS) The smaller step tablets are good for beginning work and for placing alongside of prints for "fine Note in Figure 8.3 that only a portion of the step tuning." For more extensive work, such as paper or film tablet is printed. The number of steps that can be printed testing, the 4 x 5 inch is recommended. represents the latitude or exposure scale (ES) of the photographic paper. Changing contrast grades and /?mEcrIvE Dmsrrm paper development techniques can alter this. The The print made from a step tablet can be quantitatively portion of the step tablet printed is a function of measured with a reflection densitometer (Figure 8.3). printing time and the speed of the photographic paper. When comparing relative densities, however, the eye can Therefore, if in Figure 8.3, for example, more printing be quite sufficient. In fact, the eye is more sensitive than time was given or a faster material was used, the darker the densitometer when noting barely discernible changes steps would move from left to right, that is, from lower in whites. to higher (more dense) step numbers. 66 THE PROCESS

FIGURE 8.5 EXAM IN IN^ TRANSMISSION DENSITY WIT^ T~EVISUA~ If, when a negative is printed, a step tablet is also COMPARISONDENSITOMETER included alongside, similar transmission densities of the negative and step tablet can be compared to the printed image. Using the step tablet values as a known entity, salts to elemental form. (See Chapter 7: Choose Your adjustments can be made in printing time and contrast Method, and for a more complete discussion, see to improve the image. Appendix A: The Chemistry of Developing, Contrast At the end of Chapter 9: The Platinum and Control, and Clearing Processes.) Palladium Print, see the section entitled Using the Combined Step Tablet and Print to Adjust Printing Time and Contrast; consult Plates 9.3 to 9.9 as well. SUPPLIES With practice, printing speed and paper contrast can be determined with this method. A reflective densitometer The basic supplies used for the first print, covered in is not needed. Chapter 6, are applicable here. However, since standar- dization is the goal, you must choose a metal: THE VISUALCOMPARISON DENSITOMETER Platinudpalladium using the Ratio Method, or.. . Palladium’ using the Ratio Method, or.. . If transmission density values are placed for comparison, Pure palladium using the Na2 Method, the human eye is capable of distinguishing subtle rela- tive differences. The visual comparison densitometer is And then choose the appropriate: simply a dark cardboard through which a small circular Paper hole has been cut. Looking through the aperture, shades Developer of gray can be isolated from others. Comparisons can be made from a known transmission density to match print Using the notes in Chapter 6: The First Print, you values (Figures 8.4 and 8.5). If, for example, one wishes may want to experiment a bit to determine the best to know the shadow transmission density of a negative, choice. Also, you can check with other platinum printers isolate it, and using the data in Table 8.1, find the and/or take a workshop. At this point, it is highly matching value in the step tablet. If it is step Nr. 3, that recommended that detailed notes regarding metal and transmission density is 0.35. sensitizer combinations, paper, light and distance, developer and temperature, and clearing agents be kept. It is best that they are recorded on the paper METHODSOF CONTRASTCONTROL next to the printed image.

Three of the commonly used methods of contrast ’. For those wanting to use palladium with the Ratio Method, the same control for platinum and palladium printing will be principles apply; however, instead of using the ES 1.40 midpoint covered in this text. Each uses a different oxidizer to applicable to the Pfld Ratio or Pd Na2 Methods, a Pd ES of 1.60 can “restrain” the reduction of platinum or palladium metal be substituted. CkAplER 8 CAhbRATiON 67

As a start, I would recommend one of the following: \JL: A 5s mixture of 6 drops Pd, 6 drops ferric oxa- late, and 1 drop 20% Na2 will have the same properties. 1. Platinudpalladium salts mixed 1:1; two sensiti- zers-A and B2; Crane’s Crest Natural White Wove \()I I : Before any calibration, it is best to standardize the (Platinotype) paper from Bostick and Sullivan (BS); relative humidity of your laboratory. I recommend that Potassium oxalate developer (90’ F, 32” C)3 it be between 40 and 60%. Too high or too low 2. Palladium; one sensitizer (A only); Na2 solutions: humidity will affect the properties of the paper tested. 2.5%. 5%. lo%, and 20%; Crane’s Natural Crest (See Chapter 10: Advanced Technique.) White Wove (Platinotype) paper from BS; Potassium oxalate developer (90” F, 32” C) NOTESON THE MAKINGOF TEST STRIPS Review the section on clearing agents in Chapter 4: Chemicals. As well as calibrating the light source, The making of a test strip, whether it be a printed step the effectiveness of clearing agents can be checked on tablet or a portion of a print, is no less critical than the the step tablet prints. Too strong a clearing agent will final printing of an image. Any shortcuts in technique bleach the print. Too little action will not clear the here may be compounded into a series of inaccuracies, highlights. which may become imbedded into your permanent The goal in this procedure is to establish a light- records. In addition to using paper from the same batch to-print distance that will cause at least steps Nr. 1 and as will be used for the final print, special attention Nr. 2 of the step tablet to merge with the portions of the should be paid to the coating so that an optimum print not covered by the step tablet at a printing time of amount of solution is used. For step tablets, I prefer the 10 minutes4 (400 units for the NuArc printer5). The Stouffer 4 x s.~ merging of maximum blacks will show that the printing 1. Cut the paper to a size of 4.5 x5.5 inches (this distance has the capability or “horsepower” to reach a works well when cutting an 11 x 14 sheet of paper). maximum paper black at a reasonable time. If more For use with the 0.5 x 5-inch step tablet, cut the than three blacks merge, the print-to-light distance is paper to 1.5 x 7 inches. probably too short. 2. Tape it to an 11 x 14-inch legal pad. A standard time of 10 minutes will allow easy 3. When using a S-inch Puddle Pusher’D,inject 0.5 ml of divisions and multiplication for advanced sensitometry. solution under the rod at one side of the paper and In actuality, when following this standardization, an slowly coat. (Look ahead to Chapter 9, Figures 9.10 “ideal” negative with a shadow density of 0.3 will print to 9.14.) Note that some papers have a preferred in 5 minutes with a No. 7 mixture of 3Pt, 3Pd, 3ferric printing side. For the smaller step tablets, a brush oxalate A, and 3ferric oxalate B. works best. 4. Tear off the page, leaving the strip attached. ’. Bostick and Sullivan produces two No. 2 ferric oxalate mixtures 5. If you are a beginner, I recommend letting the paper containing different amounts of the potassium chlorate restrainer: dry naturally for 5 minutes before applying the hair 0.6% (No. 2 Pt) and 1.2% (No. 2 Pd). The 1.2% produces a shorter dryer. paper exposure scale and is made to compensate for the greater scale of Pd over Pt/Pd mixtures. At this time, I recommend the No. 2 Pt 0.6% 6. Use exactly the same drying technique as you will sensitizer. For reasons to be subsequently discussed, I also prefer this for the final print. The strip can remain taped until it mixture for the pure Pd print. is almost dry. Then remove the tape and gently 3. Potassium oxalate, in my opinion, is the most natural and versatile of finish the process drying the test strip front and back. developers. With Pt/Pd mixtures it produces a slightly warm tone. In The paper can be pinned to corrugated cardboard the pure Pd print, the warmth of tone is accentuated, particularly at higher developer temperatures. Slightly heating the developer facilitates for this step, but be careful as the pins can get hot. its action, enhances the print tone, and produces a slight increase in 7. Take care not to burn the paper. The small strips printing speed. take much less heat than a larger piece of paper. Too 4. If you intend to use the information presented in Part 2: Sensitometry much heat will speed the reduction process and for the Platinum Palladium Process, print to merge steps 1, 2, and 3. darken the burned area. Step Nr. 4 should show a slight lightening of tone and step Nr. 5 a distinct lightening. (Figure 8.6). 5. Light integrators, which measure light in units, are part of most commercial plate burners. It is best if they are adjusted to allow for ‘. With the 4 x 5 step tablet, it is helpful to trim the borders on one side exposures from 4 to 10 minutes, allowing enough time for dodging and until the clear portions are at the edge. Then the blacks produced by burning. For the NuArc 26-1K or 26-1KS, it may be 400 units. For the scale can easily be seen as they merge with the maximum paper other types, some experimentation may be necessary. black. 68 THEPROCESS

T ECHN I Q u E : T I M E/ DI STANCE

1. Coat paper with a mixture’ of 50% each of sensitizers A and B with an equal amount of 50% 19 each of the platinum and palladium salt solutions l18 (see next section for coating techniques). Mark the l7 PAPERWHITE back with pencil: Mixture No. 7 PtlPd. HlI I

Use mixture No. 5s: 6 drops oxalic acid, 6 drops palladium salt, and 1 drop 20% Na2. Mark the back with pencil: Mixture No. 5s. 1-1 13 1-1 C- DISCERNIBLEWHITE

12 \’ 11 I Hereafter, I will use “A” for ferric oxalate with no restrainer and “B” for the one containing potassium 11 0.6% chlorate. 10

2. Follow the steps for drying presented in the previous 9 section on the making of test strips. 8 3. Tape the step tablet, shiny side up, to the paper with two small pieces of drafting tape. (Avoid masking 7 tape, as it has more adhesive.) You should be able to 6 read the numbers. It is helpful to place and remove 5 90% BLACK the tape from clothing a few times to remove the excess adhesive. 4 NEAR BLACK

4. Place the paper in the printing frame and choose a 3 TOTAL BLACK. AT LEAST TWO STEPS MUST MERGE print-to-light distance. Set the NuArc at 400 units. 2 5. Expose for 10 minutes, or 400 units with a NuArc printer. 1 6. Develop, clear, and dry the strip. You can also dry REndiNc, TkE STEP TAblEr TO DETtRMlNE PRINTING the strip in a microwave at a 50% setting. FIGURE 8.6 TIME 7. Look at the printed steps (Figure 8.6). There should be two to three black wedges that are maximum black, indistinguishable from each other. If there are mixture of sensitizers, comparable to a “Grade 2” too many, increase the distance to the light. If you paper. Now, it will be seen that we have at least 12 more do not have enough, decrease the distance or reset varying contrast grades available in Pt/Pd. Six have less the light integrator on your plate burner. Do not contrast than the 1:l mixture of sensitizers A and B, and worry about clear steps on the print at this time. six have more contrast, for a total of 13. They will be 8. When print distance is established (try to keep the identified as contrast grades No. 1 through No. 13. The exposure time at 10 minutes, particularly if you plan “normal” mixture of 50% each of A and B will be to use advanced sensitometric techniques), go on to termed contrast mixture No. 7. contrast control. Ratio Method Contrast Mixture TECHNIQUE:CONTRAST CONTROL Least Contrast Normal Contrast Most Contrast No. 1 -No. 7- No. 13 The step tablet print obtained in the previous test represents the contrast obtained with a “normal” The step tablet print obtained in the previous test represents the contrast obtained with a “normal” 7. If you are committed to using the Ratio Method with pure mixture of sensitizers, comparable to a “Grade 2” palladium, standardize with the palladium salt and sensitizers. (See Table 7.1.) The DR for the No. 7 mixture is 1.60. Note that Figures 8.6 paper. With Nu2 we have at least seven more varying to 8.11 pertain to a standardized DR of 1.35 (1.40). Some contrast grades. Four have less contrast than the 5s Nu2 interpolation will be necessary to adapt to a “mid” DR of 1.60. mixture, and three have more contrast, for a total of ChApIER 8 CAbbRAIiON 69 70 THEPROCESS

eight. They will be identified as contrast grades No. 1 s through No. 8s. Na2 Method Contrast Mixture Least Contrast Normal Contrast Most Contrast No. 1s 7 5s -No. 8s Contrast is determined by mixing proportions of A and B up to a total of 12 drops. (You may want to look back at Table 7.1: Standard Negative Contrast Ranges - DISCERNIBLE WHITE for Platinum/Palladium Prints to understand this con- cept.) Because of the smaller area to be coated, I chose

those combinations of 12 drops that can be divided by 2\ THERE ARE NINE STEPS two. FROM 90% BLACKTO DISCERNIBLE WHITE. 9 X 0.15 = 1.35 X

1. Cut seven strips of paper, each to the same size as 90% BLACK before. Mark them 1, 3, 5, 7, 9, 11, and 13. Here it tNEAR BLACK helps to have a number of step tablets. c- TOTAL BLACK. AT LEAST 2. Refer to A-B contrast mixtures in Table 7.1. Use TWO STEPS MUST MERGE mixture Nos. 1,3,5,7,9,11, and 13. Note that since all drops are even numbered, you can divide all proportions in half; for example, mixture No. 3 is A - 5 drops, B - 1 drop, and C - 6 drops. Coat each strip as before. If using a brush, you must start with a clean, dry brush or use the coating rod described above. NOlt : The concept of the 90% black will be further 5~2:Cut seven strips of paper, each to the same size as discussed in Part Two: Sensitometry for the Platinum/ before. Mark them 1 s, 2s, 3s, Ss, 6s, 7s, and 8s. Here it helps to have a number of step tablets. Refer to contrast Palladium Process. Briefly, the blackest portion of mixtures in Table 7.2. Here, if 1/2 portions are wanted, the characteristic paper curve does not separate easily, producing shadow areas that are blocked. simply divide the amount of sensitizer in half and substitute 10% Na2 for the 20%. When viewing a monochromatic print without another tone for comparison, the human eye will translate any 1. Print each strip at the predetermined time/distance reasonable black tone to its designed place in the total or units of light. Develop, clear, and dry all strips. scale. The 90% black meets this criterion and utilizes the 2. Align the strips side by side in good light, black on more vertical portion of the paper curve that is capable bottom. of separating tones of black. This phenomenon was 3. Following Figure 8.7, find the blackest step and go defined by Minor White to be a convincing black. (See up two steps to near black (step Nr. 4). The next Chapter 3: The Negative.) Also see Davis, Beyond the step will be the 90% black. In the illustration, it is Zone System (1998). step Nr. 5. This should be at a point where the shade is easily discernible from maximum black (Dmax). ~0tI : I have already noted that a reflection densitometer It usually lies two steps from maximum black. The is not necessary for platinum printing. At this time, you 90% black is called IDmax. Starting at the 90% may discover the sensitivity of the human eye, particu- black step, count steps until you reach the barely larly in its ability to discern tones of white. In this aspect, discernible white step. it is more accurate than the machine. ChADTER 8 CAlibnATioN 71

6. Each step of the step tablet represents 1/2 stop of 21 I I7 negative transmission density, or a 0.15 density increase or decrease (see Table 8.1). Each two steps represent one stop or a 0.3 density change. If you zoBI count nine steps for mixture No. 7, the ideal negative for that contrast mixture is 1.35 (9 x .15 = 1.35) (Figure 8.7). l7 I I PAPER WHITE 16 3~2:ff you count nine steps for mixture No. Ss, the DISCERNIBLE WHITE ideal negative for that contrast mixture is 1.35 15 11 I\ (9 x .1S= 1.35) (Figure 8.7). 14

Under normal conditions, Pt/Pd mixture No.1 should 13 produce 12 steps between 90% black and discernible 12 white. This mixture can be used with a negative of 1.8 density range (12 x 0.15 = 1.8). Unfortunately, without 11 THERE ARE 10.5 STEPS \ FROM 90% BLACKTO any restrainer, it is subject to fog. 10 DISCERNIBLE WHITE. More practical is a No. 3 mixture that provides 10.5 X 0.15 = 1.57 (1.6) 9 nearly as much density range with minimum fog: 1.6' (Figure 8.8). Note that the 90% black step has moved 8 from step Nr. 5 to step Nr. 6, indicating that the No. 3 7 mixture has a faster printing speed (112 stop). Step Nr. 6 has 0.15 or 1/2 a stop more density than Step Nr. 5; 6 90% BLACK therefore, since the same 90% black is printed though 5 it NEAR BLACK more density with mixture No. 3, it is 1/2 a stop faster 4 t than mixture No. 7. TOTAL BLACK 3 3.12: The No. 3s mixture provides nearly as much 2 density range with minimum fog: 1.6' (Figure 8.8). Note that the 90% black step has moved from step Nr. 5 to 1 J step Nr. 6, indicating that the No. 3 mixture has a faster printing speed (1/2 stop). Step Nr. 6 has 0.15 or 1/2 a FIGURE 8.8 Tkt STEP TAbltr fnoM A RATIO No 3 OR A NA~ stop more density than Step Nr. 5; therefore, since the No 3s MIXTURE. same 90% black is printed though more density with mixture No& it is 112 a stop faster than mixture No. 7. For a useful test, use the full 12 drops to make a mixture, check your laboratory lights by doing the same No. 2 step tablet print (11A and 1B). There should be no coating in the dark. Forty-watt lights at a distance of 4 fog and you should get a contrast of 1.7 (Figure 8.9). If feet should produce no fog. ffyou get fog while coating you have fog with this mixture, check your laboratory in complete darkness, the ferric oxalate is probably old, lights by doing the same coating in the dark. Forty-watt and a significant portion has gone to ferrous. See Fog lights at a distance of 4 feet should produce no fog. If versus Stain in Chapter 1 I: Problems. you get fog while coating in complete darkness, the ferric oxalate is probably old, and a significant portion Mixture No. 13 should produce seven steps from has gone to ferrous. (See Fog versus Stain in Chapter 11: 90% black to discernible white for a 1.05 to 1.10 Problems.) negative density range (Figure 8.11). Note that in this case the increased amount of restrainer used has slowed \~2: For a useful test, use the 1s Na2 mixture (see the printing speed one full stop. The 90% black is now Table 7.2). There should be no fog and you should get a in step Nr. 3. Therefore, since the same 90% black is contrast of 1.85 (Figure 8.1 0). ffyou have fog with this printed with less density with mixture No. 13, it is 0.3 or a full stop slower than mixture No. 7. Note that with this mixture, two maximum black steps may not merge. *. It is actually 1.57. In reading densities, we round off to the nearest This is not significant; we know that this mixture is 0.05. capable of producing a maximum black. 72 THE PROCESS

21 21

20 20 PAPER WHITE

19 PAPER WHITE 19

18 18 DISCERNIBLE WHITE 17 17 DISCERNIBLE WHITE 16 HI 16 15 15

14 14 THERE ARE 12.5 STEPS 13 13

12 THERE ARE 11.5 STEPS : FROM 90% BLACKTO FROM 90% BLACKTO 11 f DISCERNIBLE WHITE. 11.5X0.15=1.725(1.7) 10

9

8 + 7 J 90% BLACK 6 90% BLACK t NEAR BLACK 5 NEAR BLACK

4 t TOTAL BLACK TOTAL BLACK 3

2 ~J 1

FIGURE 8.10 TIIE STF~TAbltl ~ROMA No ISNn2 CONTRAST MIXT~IRE

Mixture No. 8s should produce seven steps from PALLADIUMPRINTING WITH THE RATIO METHOD 90% black to discernible white for a 2.0.5 to 1.10 negative density range (Figure 8.1 1). Note that in this When using pure palladium, similar tests should be done case the increased amount of restrainer used has slowed for printing speed and contrast mixtures. If the same the printing speed one full stop. The 90% black is now sensitizer BS No. 2 Pt is used (0.6% chlorate), printing in step Nr. 3. Therefore, since the same 90% blirck is speed should be approximately the same as with PtPd. printed through less density with mixture No. 13, it is Realize, however, that palladium has an inherently 0.3 or a full stop slower than mixture No. 7. Note that greater latitude (exposure scale). With a negative at a with this mixture, two maximtun black steps may not given density range, palladium will require more merge. This is not sigrzificant; we know that this mixture restrainer than PtPd to produce a comparable image is capable of producing a maximum black. and will, therefore, exhibit a slower printing speed. A negative with a 1.4 DR can print with a No. 7 Pt/Pd Compared to the standard No. 7 (normal) mixture. The same negative will require a No. 11 contrast mixture, the lower-numbered contrast mixtures contrast mixture with Pd. exhibit faster printing speeds. The higher-numbered If BS Sensitizer No. 2 Pd is used (1.2% chlorate), contrast mixtures have slower printing speeds. These pure Pd will approximate the contrast found with PtPd. differences will be quantified in Chapter 13: Using the But the increased concentration of chlorate will sig- Print Curves. nificantly slow printing speed (as well as increase ChAplER 8 CAbbRATiON 73

21 STANDARDNEGATIVE CONTRAST RANGES

20 If the tests are done correctly, there will be surprisingly 19 few differences found between one laboratory and 18 another. The characteristics are reproducible to the

17 point that Standard Negative Contrast Ranges can be listed for each combination of metal and sensitizer (see 16 Tables 7.1 and 7.2). PAPER WHITE 15 -

14 The choice of paper and developer may affect 13 printing speed. Extreme variations of developer tem-

12 perature and room humidity may cause perceptible changes in paper contrast. 11

10

DISCERNIBLE WHITE 9 1s CALIBRATINGWITH THE DICHROMATEMETHOD \ 1. Coat seven test strips as you would with Ratio A+B THEREARESEVENSTEPS FROM 90% BLACKTO Method No. 1. Use only sensitizer A. DISCERNIBLE WHITE. 7 X0.15 = 1.05 2. Mark the strips 1, 2, 4, 6, 8, 16, and 32. These numbers refer to the number of drops of 50% sodium dichromate per 200 ml of potassium oxalate developer. (See Chapter 7.) 90% BLACK C- NEARBLACK 3. The rest is the same as the A + B Method. Develop c- TOTAL BLACK at 90' F. Keep developers in marked bottles. Do not discard the developer; replenish in increments of 200 rnl with the proper number of drops of dichromate/200 ml. (See Table 7.6.)

If the tests are done correctly, you should come very anularity). If this is your choice, tests must be done close to Table 7.6: Standard Negative Contrast Range th this concentration. for the Dichromate Method. Thispageintentionallyleftblank CHAPTER 9

PLATE 9.1 IMpERIA[ DUNFS, CAllfORNlA 2001 I,? X 20 INCk PTiPd Tkls IMACIE IS bAsEd ON TkE TONES IN TkE CENTER pORTlON IT WAS PlANNFd IkAT TkEV bF IN rht ZONE Ix TO x RANGE KNOWINGTkAT "dRY dOWN" wotlld OCCUR fO[[OWINq PROCESSING, MOST Of TklS PORrlON WAS PRlNlEd TOO hGkT TO CONTRIN TEXTURE AITERdRYING. All Of TkE TONES WERE LISlblF, JUST AbOVE PAPER WklTE

75 76 THE PROCESS

The following is a comprehensive guide to the making Paper of platinudpalladium (PtPd) or palladium (Pd) Pencil prints using the Ratio, Na2, or Dichromate Methods. Plastic l-oz medicine cup or shot glass Additional variations to the basic processes are covered in Chapter 10: Advanced Technique. An algorithm of the Plastic pushpins basic procedures for making a PdPd and Pd print is Plate glass working surface (for coating rods) provided in Table 9.1. Until you become familiar with Printing frame, plate glass sandwich, or vacuum the process, I recommend that you copy Table 9.1 and easel Table 7.1 or 7.2: Standard Negative Contrast Ranges and Printers’ Rubylith’, either paper or acetate keep them in your laboratory. Discussions of the test strip and the final print are Scissors presented separately, in sequence, in two later sections Thermometer of this chapter. Reread the section on the making of a With all but the smallest negatives, it is desirable test strip in Chapter 8: Calibration. to make a preliminary test strip. It is also valuable to Additional equipment will be required beyond that concurrently print the smaller 0.5 x S-inch step tablet needed for the first print. For the sake of completeness, I along with the test strip. Each step represents a 0.15 or provide the entire list here. 1/2 stop density difference. If the test strip is not satis- factory, make adjustments in contrast and printing time by referring to the step tablet image. See Using the UTENSILS Combined Step Tablet and Print to Adjust Printing Time and Contrast at the end of this chapter. 11 x 14 corrugated cardboard Black felt tip marker Blow dryer THE TEST STRIP

Brush or coating rod (Puddle Pusher”) COATINGTHE TEST STRIP Canned air’ or air syringe

Clean blotter 1. Cut a 1 x 3-inch section of the paper you will use. Clean kraft paper or newsprint If you plan to also print the step tablet, cut two Clean towels pieces. Note the data in pencil on the back of the Clock-timer strips. Cotton applicators (Q-tips@) See The Test Strip in Chapter 8: Calibration for Cotton gloves guides in the making of test strips. Distilled water, 1 gallon 2. Choose a contrast mixture and printing time. Refer Drafting tape to Chapter 3: The Negative and Table 7.1 or 7.2: Glass beaker containing distilled water and dropper, Standard Negative Contrast Ranges. If you are 4 oz reasonably certain of the contrast mixture, you can Glass beakers or graduates mix enough material, or even coat the paper for the Hypodermic syringe for the coating rod, 1 to 10 ml final print at this time. With larger negatives, I based on print size would resist this temptation. 3. Each extreme of mixture has disadvantages. Ratio For the Na2 Method, 5- and 10-ml graduates and Mixture No. 1 has a tendency to fog (no restrainer). l-ml pipettes with catheters (see Figure 7.1) Mixture No. 13 tends to be grainy (too much Kodak or Stouffer’s photographic step tablets restrainer). As discussed in Chapters 4 and 7, the Na2 mixture 8s will provide the same ES with far less graining. ’. Due to environmental concerns, many photographers prefer not to use canned air. If your laboratory has the space, or if you are adjacent 4. Work on a clean blotter over kraft paper or to a storage area, you can rent a “C” tank of nitrogen gas. You must newsprint. When coating the test strip, place it over use a reducing valve to control gas pressure. scrap paper that can be discarded. A 8.5 x 14-inch Read Negative 1 1 Visual Assessment or Transmission Densities 1 Choose Metal Salt (C) 1 6 Drops Pt and 6 Drops Pd or 12 Drops Pd I Contrast Mixture A:B I t High - Contrast Negative Medium - Contrast Negative Low - Contrast Negative + I Contrast Mixture No. I1111111111111 I 1 2 3 4 5 6 7 8 9 10 11 12 13 (See Table 7.1 : Standard Negative Contrast Ranges for the Ratio Method) Na2 Contrast Mixture I Na2 Mixture No. (Palladium only) I1 1 1 1 1 1 1 1 1s 2s 3s 4s 5s 6s 7s 8s (See Table 7.1 : Standard Negative Contrast Ranges for the Ratio Method) Choose Printing Time 1 4 k 1 Minus 1 Stop Normal Plus 213 Stop Mix Sensitizers A+B 12 Drops and Metal Salts 12 Drops = 24 Drops or Equivalent Na2 6 Drops Ferric Oxalate A + 6 Drops Palladium Salt + 1 to 3 Drops Nu2 = 13 to 1.7 Drops 1 1 Coat Paper 1 Brush or Coating Rod Dry Coating 1 Expose to UV Light 1 1 Light Box. 3 to 12 Minutes Normal or NuArc 200 to 500 Units Normal Develop 2 Minutes I I I .L .L Potassium Oxalate or Ammonium Citrate Clear in One of the Baths, Three Times for 5 Minutes Each 1 1 1 Dilute Acid or Hypo Clearing Agent or Sulfite/EDTA Wash 15 to 20 Minutes 1 Screen - Dry Print 78 THE PROCESS

legal pad works well. After each test strip is coated, Thermometer the top page can be torn off. The sensitizer (ferric Tongs or (if you prefer) rubber gloves oxalate) will go to ferrous oxalate with time or Trays (5)in sink, the first empty to receive the exposure to ultraviolet (W)light. The ferrous developer and the second attached to running water; oxalate causes the platinum or palladium to the last three should contain 2 quarts each of convert to the metallic state, which makes the clearing agent print. (See Appendix A: The Chemistry of Developing, Contrast Control, and Clearing Processes.) DEVELOPINGAND CLEARING 5. Place proportions from droppers in a 1-02 plastic 1. Heat the developer to 90" F, and pour into first tray. cup or shot glass. Do not agitate the metal With ammonium citrate, you may wish to use it at solutions. They are in a supersaturated state. room temperature for cooler tones. More printing Shaking causes the particulate metal salts at the time will be required than with heated potassium bottom of the bottle to rise to the surface and onto oxalate. The last three trays will have equal your paper-on the sky, naturally. amounts of clearing agent (2 qts each). 6. Place all droppers back in the bottles. Never leave 2. Immerse strip(s) in developer quickly. Development an open bottle on the table. will be instantaneous. Develop for 1.5 to 2 minutes. 7. Wet the brush with one or two drops of distilled Drain the strip, rinse in running water, and place it water. Work it into the brush or follow the in the first clearing bath. Gauge the contrast and directions for the coating rod. printing time. Due to dry down, the final print will 8. Using a separate dropper stored in distilled water, be slightly darker than the strip. This part takes time place six to eight drops of coating material on and practice. The print will continue to lighten in strip(s) and immediately coat the paper. the clearing agents; don't worry, it will darken when 9. Pin the strips to the cardboard and dry in your dry. A microwave can be used to dry the test strip. usual manner. Use the dryer 8 to 12 inches away Try 30 to 50% power for 10 minutes. from paper and constantly moving. Do not burn 3. Examine the dry strip. Make sure that the highlight the paper coating. (See the next section The Final areas of the image and the step tablet have Print.) It is at this point that the most hazardous completely cleared. If not, change the concentration exposure to the metal and sensitizer salts may or type of clearing agent. Check the shadow values. occur. To prevent the particulate matter Compare to the print of the adjacent test strip. from entering the respiratory system, do this in a (Refer to Using the Combined Step Tablet and Print well-ventilated area. Keep the dryer at arm's to Adjust Printing Time and Contrast at the end of length. this chapter.) 10. Place one strip with its emulsion side against the 4. When the strip is satisfactory, coat the paper for the dull side of the negative, choosing an area that has final print. a representation of shadows and highlights. At the side, place the other strip in contact with the step tablet. THE FINALPRINT 11. Print at a predetermined exposure time. For printing in the horizontal position, printers' THE COATINGINSTRUMENTS Rubylith@ can be used to add or subtract different times. One of the secrets of good coating is to use the right amount of material (approximately eight to ten drops for each 10 square inches). Many printers err by not using enough coating material. MATERIALSUSED FOR DEVELOPINGAND The method used to measure the coating solution CLEARINGTHE TEST STRIP varies with the size of the negative. Remember, the relationships are proportional; while single drops may Clock timer be significant for a 4 x 5-inch image, they are of less Developer in stainless steel or Pyrex beaker (1 qt for consequence for 11 14- or 12 20-inch sizes. Use 11 x 14 paper) droppers of the same manufacture, particularly when Hot plate or heated stir plate measuring the ferric oxalate. For absolute measurements Image Size in Inches Total Volume of Solution

4x5 < 24 drops 5x7 24 to 36 drops (1.5 to 2ml) 8x10 45 to 60 drops (2.5 to 3 ml) 7x 17 6 ml 11 x 14 8 to 10ml 12 x 20 12 to 14ml

of minute amounts, a pipette or l-ml syringe can be used. Generally, images 8 x 10 and smaller are measured FIGURE 9.1 BRUS~ES in drops. For 7 x 17 and larger, it is easier to measure in milliliters (ml),using calibrated graduates of 5- to 10-ml size. Normally, 1 ml equals 12 to 18 drops. This is easily tested using your droppers. Table 9.2 lists suggested (During this manipulation, take care not to splash on the volumes for each print size using a brush. These volumes paper; one drop of water on the surface will produce a must be adjusted for paper type, humidity, and your permanent mark.) technique. If you err, use too much, rather than too little Brushes are cleaned and recycled by first rinsing solution. For a coating rod, reduce the amount by them in water, followed by a soak in the clearing agent. approximately 1/3. (When using hypo clear or sulfite/ethylene diamine Brushes or coating rods may be used. Consult tetraacetic acid (EDTA) agents, it is still more efficient to Chapter 5: Paper to find the best method for particular use 2-percent phosphoric acid to clean the brush.) After papers. The use of foam brushes is not recommended, as a thorough rinse, they can be hung to dry. Do not reuse they abrade the paper surface. u brush until it is dry. Some larger natural-bristle brushes come in a cardboard cover. Do not discard it, BRUSHES but replace it over the bristles before they are completely dry. This will ensure a tight grouping of the bristle tips Camel hair or Haki brushes are best for smaller prints for the next coating. (Figure 9.1). Purchase those of good quality with ferules made of plastic or stainless steel. During coating, loose M I I A number of methods have been used to indicate bristles are a nuisance. For larger (11 x 14 and up) the area to be coated on the paper. Some platinum prints, the flexible bristles of these brushes may leave printers scribe and outline with a hard pencil. Once a areas uncoated, necessitating more passes to cover the pencil mark has gone through processing, it cannot be paper. I use a high-quality, China bristle three-inch, erased. Others outline the area with masking tape. A house brush2 (hog bristle) for more body. Overly method I have found useful with thinner papers is to expensive watercolor brushes are not ne~essary.~ place a template of black construction paper, or a The brush should not be too wet or bone dry. Each rectangle drawn with a felt marker, directly under the extreme causes the material to be drawn into the bristles paper to be coated. Its outline can be seen through the instead of reaching the paper. For normal darkroom paper to determine the coating area. humidity, I place one or two drops of distilled water on the brush and work it in by rubbing it in a dry palm. COArlNG TECHNIOUE: BRUSH With most papers, regardless of how well sized, a water spot will form around the stagnant solution a few '. Note that some China bristle brushes available in paint stores have seconds after the solution contacts the paper. Therefore, been pre-oiled by the manufacturer for ease with oil-based paints. Avoid these, or remove the oils with solvents before use with Pfld. it is essential that the solution be dispersed, however 3. For the use of a wet Richeson brush on prehumidified paper, see imperfectly, as quickly as possible. After the borders Appendix G: Elements of Platinum and Palladium Printing. have been reached, the coating can be refined. 80 THEPROCESS

Put the liquid in a beaker or plastic cup (Figures the material in all directions with the brush until a film 9.2 and 9.4). Inspect the brush for any particles or covers the entire coating area. loose bristles. Examine the paper surface, blowing off Take a cotton applicator in the other hand. Now, any dust. If there is a defect, discard the paper. using only the weight of the brush, slowly pass it Holding the brush in your working hand, pour the across the image area (Figure 9.7). If a particle or free entire solution, forming a bead in the center of the bristle appears, lightly take a swipe at it with the coating area (Figures 9.5 and 9.6). Immediately sweep cotton applicator (Figure 9.8). If unsuccessful after hole in the paper; it can likely be covered during spotting (Chapter 10: Advanced Technique). To decrease the chances of this occurring, take care not to shake or stir up the bottle of metal salt. Keep in mind that this should not be the artistic part of platinum printing. Trying to perfect the coating after the paper nap has softened can ruin an image. (Softening begins 5 seconds following the introduction of liquid.) If the paper is well sized and suitable for platinum, what appear to be streaks of uneven coating will disappear during development.

Skies: If you have a landscape with a difficult “Zone VI” sky, a number of precautions can be taken to increase the odds of a satisfactory coating. After examining the paper, rather than using the center of the paper, pour the liquid onto the foreground area below the sky. Then sweep the material to the sky, making sure that it is completely covered before working in other areas. This will reduce the chance of a water spot affecting the more diffuse areas of the print. If a particle appears that cannot be immediately removed with the cotton applicator, make sure it will be two tries, quit. Otherwise, the cotton applicator will positioned in the foreground. Rotate the paper if readily mark the softening paper nap. The particle necessary. Note the area at the corner of the paper can be dealt with later, after drying, by flicking it with a light pencil mark, because once the emulsion is off with a razor blade. An undissolved metal salt dry, you may not be able to find the defect. If you do not (precipitant) may present problems. It may not be want the pencil mark on the final print, erase it before possible to remove it with a razor blade. Don’t dig a development. 82 THE PROCESS

FIGURE 9.9 TkE COATINGRods

COATINGRODS Various forms of glass rods were available in the past; now, some have been produced with a handle, facilitat- ing ease of coating. A number are available, including the Puddle Pusher’, which comes in sizes from 4.5 to 12 inches (Figure 9.9). (Sources: BS, EE) The length of rod should be slightly more than the width of your coating area. The coating rod requires practice. It is not applicable for all papers (see Chapter 5: Paper), so do some tests using only sensitizer. The thinner papers may wrinkle too soon to allow sufficient passes with the rod. A sheet of plate glass that is completely level is required as a coating surface. The emulsion is best “injected” under the rod with a

hypodermic syringe. FIGURE 9.1 1 LALINC, DOUNA Bt~d01 COATINGMATE RIA^

I : The use of a coating rod is particularly difficult handy. If you are right-handed, balance the rod on the for larger images (7 x 17 to 16 x 20). Even with thicker left side, just outside of the coating area (Figure 9.10). papers, there is a tendency to wrinkle before adequate Stabilize the rod with your left hand while you inject coating is achieved. If this happens, do not continue with a bead of liquid along the contact area between the the rod, but keep a slightly moistened brush handy to rod and paper (Figure 9.11). The liquid should be finish the job. thoroughly drawn in to create a continuous film between the rod and paper along the width of the COATING TECHNIOUE: ROD coating area. Now, using your right hand, manipulate Determine how much solution is necessary. Generally the rod so the volume of material (which should be a the rod will require only 2/3 the amount needed for a continuous bead) is still in contact with the rod but brush. Draw the solution into a syringe of appropriate adjacent to the coating area. With slight pressure, draw size. Do not use the needle. Have a cotton applicator the bead slowly across the coating area (Figure 9.12). If done properly, the paper should be completely coated. There should now be a bead on the other side (Figure 9.13). Using your left hand, “capture” it by repositioning the rod, and slowly draw it to the other side (Figure 9.14). If bare areas remain, it may be necessary to draw the material vertically across the image area. This is best avoided. You will note that the paper soon begins to wrinkle. This is the time to stop. Sop up the excess solution at the edges with a cotton applicator (Figure 9.15). Do not attempt to introduce it into the image.

THE BRUSHVERSUS THE COATINGROD Work with both a brush and a coating rod before you make a decision. There have been some questions regarding too light a coating produced by the rod. Our testing (Keith Schreiber and the author), which FIGURE 9.14 “CA~IIJRIN~”TkE BEA~[OR ANOT~ERPA55 involves the reading of Dmax produced by the brush or rod, does not confirm this. With good technique, equal results can be obtained in most cases. It is important, competence is reached, or unless the print had been however, to use adequate solution with the rod. Although made previously, it is best to include a step tablet the rod may be more economical, do not skimp to save adjacent to the print in case minor adjustments need costs. Move the rod slowly and steadily to allow for to be made. See Using the Combined Step Tablet maximum penetration of the coating material into the and Print to Adjust Printing Time and Contrast at paper. the end of this chapter.

MAKINGTHE FINAL PRINT NO1f-: Filtering coating solutions: Precipitated metal salts in the image are an annoyance that seems to COATING vary with the phase of the moon. It is best to take 1. Measure the coating solutions in a beaker or plastic precautions to avoid them at all times, as some may be medicine cup (see Figure 9.4). Until a level of impossible to remove from the final print. (See Spotting 84 THE PROCESS

cases, printers even allow the coating to dry overnight. For most papers, we found that waiting 2 to 5 minutes allows the material to saturate the surface tubules of cellulose fibers, resulting in smoother tones and less granularity. Air drying causes some side effects. As the coating soaks in, there may be a drop in Dmax. This may not be enough to be significant. (Consult the discussion of convincing black in Chapter 8: Calibration.) Depending on the paper used, there may be a minimal speed increase and a shortening of the exposure scale (ES) of the paper (less contrast). It is best to experiment using the 4 x 5-inch step tablet. (See Chapter 10: Advanced Technique for humidity studies and double-coating techniques.)

DRYING 3 Using a hair dryer at medium setting, or a drying FIGURE 9.1 5 Usiuc, rlir Corrolv A~~ICATORTO TALE Up Ekc ESS apparatus, blow dry both sides (Figure 9.16 or SUlUrlUN see Figure 10.3). (See Chapter 10: Advanced Technique, for how to construct a drying apparatus.) Always do this in a well-ventilated area. Use the blow dryer 8 to 12 inches from the in Chapter 10: Advanced Technique.) To filter your paper. The coating should become light orange coating solutions, use student-grade filter paper in a (PdPd) to orange (Pd). Be careful not to burn the glass funnel (coffee filters are not of a fine enough paper. Burning, particularly with palladium, causes grade). (See Figure 9.3.) a severe increase in printing speed. The immediate effect is seen as areas darkened to a rust color 2. Mix in Tween 20”, if desired (a little goes a long beyond the normal light-orange tone of a dried way). (Sources: BS, FR) emulsion. After developing, these areas will appear as dark blotches in and out of the image area. ‘x: 1; I Tween 20“ is a polysorbate surfactin. It has the effect of decreasing the surface tension of the coating emulsion, causing more adequate wetting of the surface fibers of the paper. With some papers (but not all), it facilitates a smoother gradation of tones. Too much will defeat the effect of the surface sizing of the paper and cause water spots. Use sparingly. It comes in a 10% solution. At the most, use one drop of 10% for 60 drops of coating. A safer way is to dilute it to a 1% solution. Shake the beaker immediately before pouring the coating material on the paper.

3. Use a brush or a coating rod as described earlier in this chapter. Allow the coating to air dry 2 to 5 minutes before drying with heat.

tr )it The effects of air drying before applying heat: Keith Schreiber and I have studied the benefits of air drying prior to heat drying. Universally, platinum printers each have their own formula for air-drying time. Times range from 1 to 30 minutes, and in some FIGURE 9.1 6 USINGTkE HAIR DRYER Inadequately drying the paper is the surest way I know of ruining your negative, short of stepping on it. Once the wet ferric oxalate/platinum salt attaches to the emulsion side of the negative, it creates a permanent stain for which I have never found a remedy. 2. Examine the dry coating with a dim light. Any spots or bristles can be scratched away using a single- edged razor blade. (It is much easier to deal with the problem now than to try to etch or spot the developed print.) Metal precipitant generally cannot be removed. Save it for spotting.

EXPOSURE 1. Sandwich the paper and the negative in the printing frame (see the discussion of printing frames in Chapter 6: The First Print, as well as Figures 6.1 and FIGURE 9.1 7 E~~OSIJREIN ilic PIATEBLIRNFR Usiruq Rtb)IirliK Tr) 6.3). Handle the negative with cotton gloves. Use Dodqr AU~B~IRN compressed air or an air syringe to clean the glass of the printing frame and to dust off the negative. If dust is continuously attracted by static charges, use DODGINGAND BURNING an antistatic solution (see Sources). Check the The platinum printer will find that routine dodging contact of negative and paper in the printing frame and burning IS not generally needed. Unlike the before placing under UV light. While looking making of a silver gelatin print, the extreme latitude through the glass, squeeze the center of the back. If and long toe (explained in Chapter 12: The Film and you see movement, the contact is bad. To remedy Paper Curves) of the platinum or palladium print the problem, add layers of felt between the paper carries tonal values throughout the scale of the image. and the back. Nevertheless, some areas, such as a disproportionately light sky, may be improved with a simple increase in Mylar: There may be a tendency for bits of paper exposure. It is here that a horizontal printing surface coating to come off on the negative. If found immedi- facing upward is appreciated. Sheets of RubylithR ately, many can be removed using the tip of the finger material can be placed on the glass (see Figure 9.17). covered by a cotton glove. If this problem is a concern, If you followed the recommendations for standardizing particularly with multiple printings, place a l-mil piece a 10-minute printing time (usually 5 minutes for a good of Mylar between the negative and the paper before negative), the RubylithR can be allowed to remain in printing. With larger negatives, however, the Mylar can position from 5 to 10 seconds, lessening the exposure to difficult to handle. your hands and eyes. Use anti-actinic glasses (see Sources). When the print is removed from the frame, 2. Set the timer for the determined time and expose the you will see a printing-out image (Figure 9.18). print4 (Figure 9.17). While this is occurring, you can begin to heat the developer and clean up. Discard the plastic cup and wash the brush, soaking it in 2% DEVELOPINGAND CLEARING phosphoric acid for 1 minute and washing again. 1. Quickly slide the print into preheated potassium Now squeeze it dry with a clean towel and hang up oxalate developer at 90 F. Another method is to dry. to place the print face up in the dry tray and rapidly pour the developer over it. Development will be instantaneous (Figure 9.19). Any portion 4. If I fluorescent bank of lights IS used as a UV light source, it mav be of the print not receiving immediate development best to leave it on during the entire printing session. The intensity of W light is quite inconsistent for a period after lighting the bulbs. will permanently streak. Never develop a print Simply shield it when not in use. (See Appendix F: Ultraviolet Light face down. Ammonium citrate developer can be used Sources for Platinum and Palladium Printing.) at room temperature for cooler tones. Printing time 86 THE PROCESS

FIGURE 9.1 8 TkF PRINlINC+-OUT IMAGt

2. Develop, with constant agitation, for 1.5 to 2 minutes. 3. Lift print by grasping generous parts of two corners and allow it to drain into the developer tray. (Take care with tongs; you may tear off a corner.) 4. With acid clearing agents, the print can be placed directly into the first clearing bath. If a sulfate or EDTA clearing bath is used, rinse in running water before the first bath. Clear for 5 minutes with constant agitation (Figure 9.20). 5. Clearing in the second and third baths will also be 5 minutes each. As the paper becomes soaked, more care is needed in transferring it to avoid tearing. The final two baths require only intermittent agita- tion. When the first bath becomes cloudy, empty it and move the second and third baths over. Refill the first clearing tray with new solution, now making it the third bath. For an exhibition-quality print, the last bath should always be completely clear. 6. If residual print acidity is a concern, a final soak for is decreased approximately 1/2 a stop (O.IS), 5 minutes in sodium carbonate or sodium acetate requiring about 30 to 50% more exposure. can be done before washing. (See Chapter 4: Chemicals.) wit: Although we generally can work safely under a 7. The final step is a 15- to 30-minute wash in running 40-watt bulb, the metal salts are extremely sensitive to water. Either a hose or siphon can be used. Avoid light at the instant of reduction. This may cause black having water strike the print directly from the top streaking from areas of intense black to extreme white. (you will punch a hole in the print). Generally, Following the suggestion of Jim Enyeart, I turn off all platinum prints do not require as much washing as lights except for a distant reference light before applying silver prints, but intermittent complete changing of the developer. The room can be fully lighted after the water is recommended. first few seconds. (See Chapter 11: Problems for other 8. After washing, place the print, face up, on a clean suggestions to avoid this.) blotter or drying screen (see Figure 2.5). DRYDOWN the small aperture in the visual comparison densitometer, the values can be isolated from others. Comparisons can During the tests in Chapter 8: Calibration, you be made to match print and step tablet shades of gray. may have noticed that the prints darkened during the drying phase. Silver printers know this phenomenon as Use the following principles: “dry down” and plan on it during the printing of an Shadow values are changed by printing time. image. Dry down in PdPd printing is even more pro- Highlight ilalttes are changed by contrast mixture. nounced, particularly with pure palladium. When plan- ning white textures to be just above paper white, it is When both shadows and highlights are too dark, necessary to base the printing time on a dried test strip. In reduce printing time. many cases the textures will not be evident until the next When both shadows and highlights are too light, morning. (See Plates 9.1 and 9.2; see also Chapter 10: increase printing time. Advanced Technique for print finishing.) When shadows are good and highlights are too dark, shorten the scale by going to a higher contrast mixture. Use approximatelys the same printing time. USINGTHE COMBINEDSTEP TABLET AND PRINT When shadows are good and highlights are too light, lengthen the scale by going to a lower contrast TO ADJUSTPRINTING TIME AND CONTRAST mixture. Use approximately the same printing time. I have recommended that a small, 0.5 x 5-inch step When shadows are dark and highlights are good, tablet be included adjacent to the print. The following shorten the scale by going to a higher contrast sections represent examples of how printing time and mixture. Use less printing time. contrast can be modified using the step tablet as a When shadows are light and highlights are good, reference. A transmission or reflection densitometer is lengthen the scale by going to a lower contrast not required to use this technique. mixture. Use more printing time. When both shadows and highlights need correction, alter the scale by going to a different contrast mix- THE VISUALCOMPARISON DENSITOMETER ture. Change the shadows by altering printing time. As shown in Chapter 8: Calibration, if transmission density values are in place for comparison, the human ’.We know that changing the contrast mixture will have a small effect eye is capable of distinguishing subtle relative differences on printing time. Therefore, printing is slightly altered by contrast (see Figures 8.4 and 8.5). The same principles can be mixture. It may be not enough to notice, hut use a test strip. As we applied to reflective densities. Looking at a value through shall see in Chapter 13: Using the Print Curves we can accurately calculate both variables. For the purposes of illustration, I have placed seven visual comparison densitometer is helpful to isolate printing combinations together (Table 9.3). A print tones. “good” print has been located in the center for reference (Plate 9.3). Although the limitations in BOTHSHADOWS AND HIGHLIGHTSARE Too DARK reproduction may not convey the nuances found in the actual prints iPlates 9.3 to 9.9), using the 1. Find the textured shadow area. In this case, it is too following graphic examples will allow you to dark (Figure 9.21. Plate 9.4). visualize the differences between the reproductions. 2. Find the print shadow value in the step tablet. It is When doing these corrections on actual prints, the step Nr. 3. Print Shadow Print Highlight Print Shadow Print Highlight

Desired Shadow Desired Highlight

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 I8 19 20 21 - d + Both shadow and highlight values require a 0.15 correction. T Shadow values require no correction To lighten highlights, decrease contrast 0.15 Use essentially the same printing time

FIGURE 9.23 Skadous ,IRE c,ood Hic,hlic,krs RE Too dnRk Print Shadow Print Highlight Desire[ Shy Desired, Highlight / 5. Find that highlight area in the step tablet. In this case, it is step Nr. 12. 6. Find the step tablet value that you want for textured highlight. In this case, it is Nr. 11, 0.15 darker than - c Nr. 12. Both shadow and highlight values require a 0 15 correction 7. To make a print with both shadow and highlight values 0.15 darker, increase printing time by 50% FIGURE 9.22 Bork sk~dousand l-ii(,ljlic,liis ARC ioo lic,kr (1/2 stop).

SHADOWSARE GOOD,HIGHLIGHTS ARE Too DARK 3. Find the step tablet value where you want your print shadow value to fall. In this case, it is step Nr. 4, 1. Find the textured shadow area. It is good 0.15 lighter. (Figure 9.23, Plate 9.6). 4. Find the print highlight area. In this print, it is too 2. Find the print shadow value in the step tablet. It is dark. step Nr. 4. 5. Find that highlight area in the step tablet. In this 3. Find the step tablet value where you want your case, it is step Nr. 10. print shadow value to fall. In this case, it is step Nr. 6. Find the step tablet value that you want for textured 4, the same value. No change in printing time is highlight. In this case, it is Nr. 11, 0.15 lighter than indicated. Nr. 10. 4. Find the print highlight area. In this print, it is too 7. To make a print with both shadow and highlight dark. values 0.15 lighter,6 reduce printing time by 1/2 stop 5. Find that highlight area in the step tablet. In this or 33%. case, it is step Nr. 10. 6. Find the step tablet value that you want for textured highlight. In this case, it is Nr. 11, 0.15 lighter than BOTHSHADOWS AND HIGHLIGHTSARE Too LIGHT Nr. 10. 7. To make a print with shadow the same, and 1. Find the textured shadow area. In this case, it is too highlight values 0.15 lighter, shorten contrast scale light (Figure 9.22, plate 9.5). by 0.15. (Use a higher-No. contrast mixture.) Use 2. Find the print shadow value in the step tablet. It is essentially the same printing time, or increase by step Nr. 5. 10%. (See Standard Negative Contrast Ranges in 3. Find the step tablet value where you want your print Chapter 7: Calibration.) shadow value to fall. In this case, it is step Nr. 4, 0.15 darker. 4. Find the print highlight area. In this print, it is too SHADOWSARE GOOD,HIGHLIGHTS ARE Too LIGHT light. 1. Find the textured shadow area. It is good (Figure 9.24, Plate 9.7). 2. Find the print shadow value in the step tablet. It is '. For changing contrast, refer to Tables 7.1 and 7.1:Standard Negative Contrast Ranges for the Ratio and Na2 Methods. Note that step Nr. 4. with the Ratio Method, changes in the .15 or .OS range can be achieved 3. Find the step tablet value where you want your by using the even-No. mixtures. print shadow value to fall. In this case, it is step 90 THE PROCESS

Print Shadow Print Highlight Print Shadow Print Highlight Desired Shadow Desired Highlight Desired Shadow Desired Highlight 11

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 T c T Shadow values require no correction. To darken highlights, increase contrast 0.15. Shadow values require a 0 15 correction To keep highlights the same, Use essentially the same printing time. decrease contrast 0 15 Use less printing time

FIGURE 9.26 SkAdms ARt roo Iiqkr Hic,kliqkrs ARF Good

Print Shadow Print Highlight 5. Find that highlight area in the step tablet. In this Desired Shadow Desired Highlight case, it is step Nr. 11. \I 6. To keep the highlights at step Nr. 11 while raising shadow values, the contrast scale must be shortened by 0.15. 7. Printing time must be decreased 33% and contrast 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 shortened by 0.15. - T Shadow values require a 0.15 correction. To keep highlights the same, decrease contrasr 0.15. Use less printing time. SHADOWSARE Too LIGHT, HIGHLIGHTSARE GOOD 1. Find the textured shadow area. It is too light (Figure 9.26, Plate 9.9). 2. Find the print shadow value in the step tablet. It is step Nr. 5. Nr. 4, the same value. No change in printing time is 3. Find the step tablet value where you want your print indicated. shadow value to fall. In this case, it is step Nr. 4. 4. Find the print highlight area. In this print, it is too Printing time must be increased 50%. light. 4. Find the print highlight area. In this print, it is good. 5. Find that highlight area in the step tablet. In this 5. Find that highlight area in the step tablet. In this case, it is step Nr. 12. case, it is step Nr. 11. 6. Find the step tablet value that you want for textured 6. To keep the highlights at step Nr. 11, while highlight. In this case, it is Nr. 11, 0.15 darker than lowering shadow values, the contrast scale must be Nr. 12. lengthened by 0.15. 7. To make a print with shadow the same, and 7. Printing time must be increased 50% and contrast highlight values 0.15 darker, lengthen the contrast lengthened by 0.15. scale by 0.15. (Use a lower-No. contrast mixture.) Use essentially the same printing time, or decrease by 10%. Mo R E COMBI N AT I o N s We have been working in half-stop increments. For each two-step correction, one full stop is needed, either SHADOWSARE Too DARK,HIGHLIGHTS ARE GOOD halving or doubling printing times or contrast mixtures, 1. Find the textured shadow area. It is too dark (Figure and so on. When there are more extensive discrepancies 9.25, Plate 9.8). between desired shadow and print values, the principles 2. Find the print shadow value in the step tablet. It is discussed must be brought together to make the final step Nr. 3. print. As corrections get more complicated, more test 3. Find the step tablet value where you want your print strips are needed before the final print is made. When shadow value to fall. In this case, it is step Nr. 4. the principles discussed in Chapter 13: Using the Print Printing time must be decreased 33%. Curves are utilized, the initial test prints can be made 4. Find the print highlight area. In this print, it is good. with more accuracy. ’. Also see Appendix G: Elements of Platinum Printing.

91 92 THE PROCESS

MASKINGOF NEGATIVES

The material presented here is courtesy of Tom Millea. The methods previously described will show the black brush strokes around the print. If you prefer a white border, you must mask the negative before printing.

MATERIALS Metal straight edge Printer’s red masking paper (Rubylith@) Ruby tape, 1/4 inch (available from any print shop) Self-healing cutting base (Source: LI) X-ACT0 No. 16 blade (Sources: GA, LI)

PROCESS 1. Scribe on the red masking paper the borders you wish to create for the final image. Usually, this is done to just eliminate the base + fog portion of the negative; however, the image can be cropped if FIGURE 10.1 MAskiNG of TkE NEGATIVE desired. This is a delicate operation. For the first time, you may want to ask to watch a printer to do TABLE 10.1 ORdtR of MATERIALSIN rkt MnsklNq of A NE~AIIVE it. 2. Working over the cutting base, carefully cut along Masking of the Negative the lines. Take great care at the corners, as any h Glass defects will show at the corners of the final print. Printer’s Mask 3. In coating the paper, you may not want to show Negative pencil marks. (They will not erase after develop- Paper ment.) It is best to use the black construction paper U Back or Base or felt marker template (discussed in Chapter 9: The Platinum and Palladium Print) to demarcate the coating borders. light or daylight. Have enough light to see well for 4. Place the negative, dull side up, over the opening coating. Dry the paper under a dim incandescent light and tack down two sides (the base +fog area) with (two 40-watt bulbs at least 4 feet away). During the two or more pieces of ruby tape (Figure 10.1). At first instant of development, turn off the lights this time, the image can be cropped if so desired. (see Chapter 9: The Platinum and Palladium Print). 5. Place the negative with the dull side against the The efficacy of the safelight is easily tested (see coated paper. In a printing frame you will have the Chapter 11: Problems). items listed in Table 10.1. 6. Print accordingly. If a border is visible around the image, you have fogging or staining problems (see RELATIVEHUMIDITY IN THE LABORATORY Chapter 11: Problems). Relative humidity that is too high or low may affect the absorbency of the paper to be coated. My laboratory is WORKINGLIGHT maintained at a humidity of 50 to 60%, which gives consistent results with minimum solarization. For Some platinum printers have recommended the use of a reproducible results, once a satisfactory humidity has yellow safelight during coating. My tests have shown no been found, it is recommended that you maintain it. It is difference between a safelight, a low incandescent light, also recommended that you use this environment to and complete darkness. Avoid fluorescent light, bright store the paper at least 8 hours before coating. Coating ”. should be done in the wet area of your lab (see Chapter L. I

2: Setting Up a Laboratory). Providing that you do not 11.8 have forced-air heating, the dampness from the sinks tends to stabilize a moderate amount of moisture in IDmax=l35 the environment. Also, as 40-watt safelights must be in the developing area, it is the most convenient space to work. If you find unusual absorbency or graininess in your paper, you can correct the situation by exposing DR=129 the paper overnight to a humidifier or dehumidifier, depending on conditions. Be aware that extremes of humidity will change the printing speed and the exposure scale (ES) of a particular paper. (See the next . IDmin = 0 06 section.) 30 27 24 21 16 1.5 1.2 0.9 0.6 0.3 0.0 For contrast control by humidity, see the references FIGURE 10.2 EffFCTS Of HUMidiflcATioN ON FAbRIANO ARTISTiCO to the Maldemare and Ziatype Web sites in Chapter 7: PAPERCURVES. Choosing a Method. CURVE1 : CONTRO[.Rod COATiNq; A Typicnl PAPERCURLE wiTk AN ES 01 I 20; DMAX1.3 5 CLIRVE2: Rod WlTk HUMidificATioN; NOTETkAT TkE PRINTING, SPEEd \#AS INCREAStd by 213 STOp, ANd TkE ES dECREASEd TO 0.95 WTII THE EFFECTSOF HIGHPAPER HUMIDITY SkORTENIN(, Of TkE pApER TOE; DMAYI .30 CGRVE3 B~iskwlTk HuMidlficATioN. HERE,4 dAMp RickEsou Many printers humidify their paper before coating. bRusk \LA5 Ustd TO \LORk ThE COATINC, INTO TkE pApER fibERS; Some processes, such as the Ziatype and the Malde/ COMPAREd TO TkE Rod, TWICE TkE VOlUMt Of COATING WAS UsEd; NOTE Ware process depend on humidity during the exposure rkt 1.50 DMAX.This EQUATES TO A I . 3 5 ES 90% bhck. SkAdow VALUES CAN bE MAiNTAiNEd AT Tkl5 [EVE[, wkilE wlTk OTkER to ultraviolet (W)light to get a printing-out image, TECkNiQUES. 1 55 bould RtpREsENT UNTEXTUREd DMAX.1 .20 ES which can be examined before actual development. In (SAME AS TkE CONTROI). place of the standard ferric oxalate described in the text, CVR~E4: INAdEQiiATE COAIIN~wirk Rod; TkE COATING kAS bEtN they use the hygroscopic effects of ammonium ferric AbSORbEd iNTO Tkf pApER flbERS; DMAXIS ON[).’ 1 .20,ANd oxalate to retain moisture. The water within the paper SiCiNlfiCANI SO[ARiZATiON kAS OCCURREd. fibers provides a vehicle for the reduced platinum and palladium to coalesce, thus forming the image. (See Appendix A: The Chemistry of Developing, Contrast that receive the most light, usually the brush strokes Control, and Clearing Processes.) There are many around the image, may actually end up lighter than the reported advantages of paper humidification. shadow areas of the image. (See Figure 10.2, Curve 4.) If the print is to be matted, this should be of little consequence-particularly if the shadows are planned as 90% black. PREVENTIONOF SOLARIZATION Solarization can also occur when the coating is too Solarization differs from the Sabattier effect. The thin or the paper too dry. Using a heavy coating on pre- Sabattier effect involves the reversal of the silver image humidified paper will greatly diminish this reaction. upon introduction of light during the development Some printers re-humidify the coated paper before process. True solarization is based on the concept that, exposure. (See Appendix G: Elements of Platinum and given a layer of metal salts, reduction may occur first on Palladium Printing.) the surface, blocking the deeper layers from receiving as much light as adjacent areas (known as plating). Unlike processes such as albumin, where the coating is held in THE ELUSIVEDMAX the surface by a substrate, the platinudpalladium (Pt/ Pd) coating has been absorbed into the paper with too As defined in Chapter 3: The Negative, Dmax is the little on the surface to produce any “self-masking” maximum black a particular metal-paper combination effect. reaches. It is usually found in the brush strokes where Palladium, most commonly, has a tendency to the W light has not been blocked by film base plus fog solarize under supermaximum exposure. The areas (B+F). This is read by a reflection densitometer and is 94 THEPROCESS reported in logarithmic values. In the PdPd process, this exposure scale and subsequent shortening of the toe. usually is 1.30 to 1.40, although a 1.50 density can be Therefore, in the printing of a set negative, the highs obtained with special techniques. IDrnax is defined as would be consistently at the toe with all three methods. the darkest areas within the image and is represented in However, with the rod, the shadows were depressed by the Zone I11 shadow values. This would generally be a 2/3 of a stop, well into the Zone I1 range. No 90% black. solarization was observed. One of the benefits reported for paper humidifica- tion is an elevation of Dmax. Using the laboratory and a A Rrisrico reflection densitomer, I duplicated some of the proce- Here, the greatest changes were observed (Figure 10.2). dures followed for paper humidification to obtain The process of humidification increased paper absor- measurable data. bency due to hygroscopic effect. Therefore, more coat- ing was needed to compensate for that absorbed by the

HUMlDlFlCATlON paper fibers. I constructed a humidification chamber at 75% humid- ity and humidified paper at that level for 10 minutes. I 0B s E RVAT I o N s used three papers: Crane’s Platinotype, and the heavier papers Platine and Fabriano Artistico. I acidified the 1. Humidification can prevent solarization; however, Artistico with 1% oxalic acid. One set of the three adequate amounts of coating material must be used papers was humidified before coating, and it was air to compensate for the increased absorbency of the dried. Another set was re-humidified after coating and paper. In humidified paper, the ferric oxalate and before exposure. A third set, to serve as a control, was palladium salt molecules, due to hygroscopic effect coated and heat dried in the normal manner. of the wet paper, become suspended in the ‘‘gel’’ of the moistened paper fibers. At the time of UV exposure, the ferrous oxalate bonds with the COATING reduced palladium below the surface and immedi- The papers were coated using two methods: rod coating ately coalesces. and with a moistened Richeson brush. Manipulating the Since this occurs within the paper, leaving less brush took twice the volume of coating material as the palladium on the surface, there is little chance of rod. plating. Also, as shown by tests, more coating material is needed to compensate for that absorbed EXPOSURE by the paper. All papers were exposed to a Stouffer Step Tablet at 350 2. Other than the prevention of solarization, thinner units on a NuArc 26.1K plate burner. The re-humidified papers, such as Crane’s Platinotype, do not benefit papers were protected from the step tablet by a sheet of considerably from humidification. This is substan- 1-mil Mylar. tiated by the modest Dmax of prints made with the ammonium-based processes, such as the Ziatype, CRANE’S PLATINOTYPE where considerable humidity is maintained by the When compared to the control, Crane’s Platinotype, ammonium ferric oxalate. Crane’s Platinotype whether humidified one time or re-humidified a second exhibited a printing speed increase upon humidifi- time, exhibited the same results. There was a 2/3-stop cation. increase in printing speed with a consistent exposure 3. Platine and other papers with adequate surface scale. There was no increase in Dmax. In fact, in sizing may not benefit as much from humidification some cases, it decreased from 1.35 to 1.30. The same as previously reported. Instead, the printing speed results were obtained when the paper was allowed to air increase, with the decrease in ES, compacts the tonal dry without humidification. No solarization was values and simply produces untextured blacks more observed. into the Zone I1 range. Considering the absence of solarization and metal molecules imbedded well into PLATINE the heavier paper fibers, some images may take on a Dmax was the same on Platine paper regardless of the more dramatic effect, approaching posterism. presence or absence of humidification. Notably, the 4. Heavy watercolor papers, after acidification, are curve from rod coating increased the printing speed 2/3 indeed capable of taking on an increased Dmax of of a stop, with a corresponding decrease of 0.2 of the about 0.10 to 0.15 above that obtained with more traditional techniques. However, using a moistened, A sizing medium will provide a body to the coating non-abrasive brush, excess coating material must be material. My tests show that it makes coating easier worked into the paper fibers. because it holds the emulsion more on the surface and prevents wash off during development. Dmax is HYDROGENPEROXIDE increased (+0.1 reflective density). While many sizing agents will go into solution with The use of hydrogen peroxide to prevent fogging has distilled water, at this time I have found no medium other than polyvinyl alcohol that will go into complete solution been suggested. Some workers also use it as an oxidizer for contrast control. Expect some fogging when no when added to the acid-coating material. If you plan to restrainer has been used. test any ingredient, add it to only the ferric oxalate and If you are using only ferric oxalate solution A with examine the effect before adding the metal salt. (While some ingredients will go into solution at a neutral pH, no restrainer, one drop of 3% hydrogen peroxide per ml of coating material will prevent some fogging by most will congeal in the acidic ferric oxalate.) temporarily converting the minimal amounts of ferrous Polyvinyl alcohol 5% is available as a sizing agent. oxalate to the ferric form. This slightly decreases the Used at 1 to 2 drops per ml of coating material, it will exposure scale (the same as adding one drop of solution provide some body to the coating. Its effectiveness is dependent on the paper, so it is necessary to do visual B). (See Appendix A: The Chemistry of Developing, Contrast Control, and Clearing Processes.) tests. (Source: BS) With one drop of sensitizer B per 11 drops sensitizer A, or one drop per 12 of 2.5% Na2, no fogging should occur. If you routinely need hydrogen peroxide to IMAGEHUE prevent fogging, you may have problems. (See Chapter In addition to the effect of the platinum and/or 11: Problems.) palladium metals, image hue2 can be controlled by the sizing, choice of developer, temperature, and toning. BRUSHES Paper base hue will also affect the image. Early in my tests, I tried dozens of different brushes, hoping to solve coating problems. Eventually, I found SIZING that most problems were related to papers. Today, Gelatin sizing produces blue-black hues, particularly many papers have inadequate surface and internal sizing with platinum. Starch sizing (used by most paper or pH to make them suitable for platinum printing manufacturers) produces warmer, brownish hues. (see Chapter 5: Paper). With suitable paper, many brushes will work. I believe that some unusual coating methods are used because of inappropriate paper. DEVELOPERAND TEMPERATURE CONTROLS Don't waste time and chemicals on bad paper. (See When doing the paper tests for this second edition, I Brushes in Chapter 9: The Platinum and Palladium noted that new developer produced a predictable sepia Print.) hue, modified only by the choice of metal and paper. However, I also noted the changes when using the same '%: :i For instructions on the use of a wet Richeson developer a second time. This effect became more brush, see Appendix G: Elements of Platinum and pronounced with each subsequent use. Palladium Printing. At a certain point, the platinum and/or palladium ions residual in the developer exert a profound effect on THE USEOF SIZING MEDIUMIN THE SENSITIZER the hue of the print, more so than many other procedures used to modify image color. Since Pt/Pd Technically, the coating material is not an emulsion printing is basically a print-making process, we do unless it contains an emulsifying ingredient. An emulsifier will theoretically add body to the coating, keeping more 2. of it on the surface of the paper. The best product, For the purposes of this text, hue is generally used to denote the color changes related to metal choice, sizing, developer, and toners. (Blame Liquitex acrylic sizing medium (made by Binney Smith), Photoshop"'.) Tone is generally used to describe the smoothness of is, unfortunately, no longer applicable as they have texture or lack thereof. However, it will also be used in the section on changed the formula. spotting to describe progressions from paper white to black. 96 THE PROCESS not expect (or welcome) the predictable mechanical have been reported. Variations between workers are perfection noted with the silver gelatin print. The probably explained by differences in technique, paper, probability that each image from the same negative and developer. For our tests, we used the Ratio Method may have subtle differences gives our process one of its with Crane’s Crest Natural White Wove paper, devel- many charms. oped in potassium oxalate at 90” F. Proportions of pla- tinum/palladium at 5:1,3:2, 3:3,2:3, and 15were used. Contrary to some findings that the same hue of a METALIONS IN THE DEVELOPER 50% mixture can be reached by using 1:5 platinum/ Richard Sullivan has raised a number of questions about palladium blend, we observed that the 1:5 hue was the reuse of developer. If one uses the same developer for considerably warmer and more closely approximated a both PtPd and pure palladium prints, the developer pure palladium print. There were visible changes from becomes loaded with both platinum and palladium the extremes of mixtures, providing increments between molecules. When using this developer, therefore, you the pure platinum, 50% PtPd, and the pure palladium cannot produce either a “pure” platinum or “pure” print. Perhaps others have produced different results and palladium print; each has a minuscule amount of the have found a way to economize in the PtPd ratios. other metal. In the case of pure platinum prints, if toning, redevelopment, or intensification is anticipated, TONING it may be wise to do some tests with prints processed in new developer. Gold chloride, mercuric chloride, potassium phosphate, uranium nitrate, lead oxalate, and other substances can be used to alter image color, either in the sensitizer or COMBINATIONSOF PLATINUM AND PALLADIUM as a toning bath. Of these, I will be discussing only gold By combining proportions of metal salts with developer chloride. (See also Gold Chloride in Chapter 4: and temperature variations, image hues from neutral Chemicals.) gray to warm sepia can be obtained (Table 10.2). When Gold chloride 5% may be used in the sensitizer or printing in palladium with the Na2 method, the as a direct toner to cool the image hue of a platinum or characteristic palladium hue is maintained throughout PtPd print. In the sensitizer, place one drop of gold most contrast grades. Only when multiple drops of chloride per ml of coating material. This may also 20% Na2 are added to the basic 12 drops, will the image reduce granularity. As a toner, brush gold chloride take on some of the platinum characteristics. As stated, directly onto the wetted print, usually with glycerin to substituting a citrate developer for the potassium control application (Crawford, 1979; Nadeau, 1994; oxalate will produce hues quite similar to the traditional Sullivan and Weese, 1998). When the desired hue is 50% platinum-50% palladium print (see Table 10.2). reached, rinse the print and place for 1 minute in Dektol; For combinations of platinum and palladium other then wash. (See Chapter 4: Chemicals, for gold-toning than the standard 50% ratios, a number of effects on hue formulas.)

TABLE 10.2 PRINT HUEAS RtlATEd TO META~SALT. DEV~OPER,ANd DELELOPERTEMPERATURE

Hue Metal Developer

Cool fi Platinum Ammonium citrate 68 F 50% PlatinundPalladium Ammonium citrate 68” F Platinum Ammonium citrate 90” F 50% PlatinundPalladium Ammonium citrate 90” F Palladium Ammonium citrate 100 F Platinum Potassium oxalate 68” F Platinum Potassium oxalate 90 F 50% Platinum/Palladium Potassium oxalate 90 F Palladium Potassium oxalate 90” F Warm Palladium Potassium oxalate 100 to 110 F C LY CER IN DOUBLECOATING

At the turn of the century, many pictorialists used Keith Schreiber’s and my studies have demonstrated glycerin to selectively develop the platinum print. Much that the efficacy of double coating is dependent on the of the historic literature, including the writings of Alfred paper used. With many papers, if well coated, a single Stieglitz, contains references to this technique. While the coating is equal to, and frequently superior to, a double most grievous practices of romantic expression might coat. The observation that some of the more alkaline not fit in with our time, this practice can be a valuable papers improve by double coating may be explained by tool for those who wish another method of image the fact that the first coat simply acidifies the paper to manipulation. better receive a second coat; the same result may be Glycerin can be obtained from a pharmacy or any more economically achieved by acidifying the paper chemical supplier. It is mixed with developer, either in a with a pre-coat of 1% oxalic acid. (See Chapter 5: single bath or in various concentrations. Because Paper.) proficiency requires some practice, it is best to start Some papers, usually the heavier ones, may benefit with only one concentration of SO% glycerin and 50% from double coating with a smoother tone and a deeper developer, which will be used in conjunction with 100% Dmax. With most, the double coat mucks up what could developer. After beginning with this concentration, have been a good coating, creating blotches and a other ratios can be tried. diminished Dmax. You must test the paper using your own technique. Here, the Stouffer 4 x 5 step tablet is valuable. The steps M ATE R I A LS are large enough to gauge the smoothness of tone and Brushes to apply glycerin and developer Dmax. You do not need sensitometric machinery to visually assess the differences. Developer For double coating, some printers dilute each Glass sheet, slightly larger than the paper application of coating agent with 30 to 50% distilled Glycerin water. Allow the first coating to air dry for 3 to 5 Jars to contain the various concentrations of minutes, then heat dry and recoat. If you decide to glycerin and developer double coat your final print, you must anticipate a change in printing speed and do the appropriate tests. Running water Simili Japon and Platine papers both can benefit from double coating. With these papers, Keith Schreiber 1. The print is exposed to UV light in the usual way. uses the standard concentrations of ferric oxalate and Some recommend overexposure. metal salts. With the Simili paper, a few drops of Tween 2. Arrange three jars: one with 100% glycerin, one 20‘ are added to the coating material. (See Tween 20@’ with SO% each of glycerin and developer, and one in Chapter 9: The Platinum and Palladium Print.) The with 100% developer. first coating is allowed to air dry only for 1 hour. 3. Wet the glass with pure glycerin and “stick” the Following the second coating, the paper is heat dried in print onto it, face up. Immediately cover the print the normal manner. The Dmax of both papers is with pure glycerin. You will see the printing-out increased significantly, as well as smoothness of tone. image. Because of the increased intensity of black, the ES of the 4. Using the two solutions containing developer, paint paper is somewhat shortened. the image to enhance selected areas. The process can Platinum printers throughout the world have devel- be arrested at any time by flooding the area with oped many other unique variations for double coating. pure glycerin or using blotting paper. For more information, the reader is encouraged to 5. When satisfied, thoroughly flush the print with explore the many Web sites available on this subject. running water and clear. Richard Sullivan and Carl Weese describe a brush development that utilizes ammonium ferric oxalate and DRYINGOF THE COATING potassium chloroplatinite. The technique is similar to the one just described, but uses only a cold bath or Natural drying in room air can be precarious; times are potassium oxalate developer and glycerin (Sullivan and dependent on temperature, humidity, and the choice of Weese, 1998). paper. Also, with some papers, air drying may change 98 THE PROCESS the printing characteristics. (See Relative Humidity in the Laboratory and The Effects of High Paper Humidity in this chapter.) It could take long enough to cause some of the ferric oxalate in the coating to go to ferrous and result in fogging. Here, an alternative to overnight drying is to allow the paper to set for 1 hour, and then dry with a blow dryer with the heat turned off. Most platinum printers use an application of heat to dry the emulsion. As discussed in Chapter 5: Paper, the paper should be allowed to air dry at least 5 minutes (or Particle more) before heat is applied. The common method is to - gaard use a hair dryer or a drying cabinet. With a hair dryer, - scrccr there is always the tendency for uneven drying and the possibility of burning the coating. Also, the close 2aarc proximity needed to operate the hair dryer may expose FIGURE 10.5 T~EDRY IN^ A~~ARATUS the respiratory system to the bits of coating material that can enter the air when in the dry state. The drying cabinet is superior for even drying, but few people have access to one of sufficient size. A commercial dryer is available from Edwards Engineering. (Source: EE) To help solve these problems, I have devised a 3. Cut two holes 1 inch smaller than the outer method utilizing two commercial hair dryers and diameter of the diffuser cones along the center of the diffusing cones, both available at a beauty supply store. long axis of the particleboard. Place the centers of the holes at the measured distance between the centers of the cones. The dryers should sit over the MATERIALS board with the cones pointing downward over the holes. Fiberglass window screen, 2 x 3 feet 4. Attach the dryers and diffusing cones with the wood Lumber, 1 x 4 inches and eight 1-inch, round- screws. You may want to catch the lip of the cones headed wood screws with the heads of the screws rather than puncture Particleboard, 5/8 x 12 x 24 inches the plastic. Two high-quality commercial hair dryers ( 1200- 5. Make a rectangular base with the lumber to support 1400 watts) and diffusing cones3 the window screen. Cut away some wood to allow for ventilation. Place the support and the screen on Two swag hooks and cord your counter. 6. Place the swag hooks on the ceiling directly over the METHOD screen, about 20 inches apart. Center their position with the axis between the dryers. Making loops with 1. Tape the handles of the hair dryers together, the cord, pass each one around one end of the overlapping them so that the nozzles are at opposite board. Notch the board 2 inches from the ends to ends and both are pointing the same direction prevent slippage. Suspend the entire apparatus from (Figure 10.3). the ceiling so that the board rests 3 to 4 inches over 2. With the diffusers installed on the dryers, place them the screen. on the board, open end down. Measure the distance 7. With the freshly coated paper lying face up on between the centers of the cones (it should be about the screen, the board with the attached dryers is 10 inches). gently rocked back and forth over the paper. By periodically maintaining that motion and rotating the print, even drying should occur in 3 to 5 minutes. The combined current draw of 2400 to 3. High-quality dryers, usually special-ordered from beauty shops, are in the $60.00 range. Unlike the less expensive variety, they can be quite 2800 watts will strain the circuit breakers, so you efficient at medium power, which extends the life of the diffuser and will probably want to choose a circuit with no other minimizes the chance of burning the print. load. PREPARATIONOF THE FINALPRINT

DRYING If you are in a low-humidity environment, remove the print from the drying screen before it is bone dry and press it under a heavy object. (An old chemistry book will do.) After a few hours, flatten the print under a mounting press set at 200" F. Protect both sides of the print with archival board.

PRINCIPLESOF ETCHING AND SPOTTINGPLATINUM/ PALLADIUMPRINTS

M ATE R IA LS

#000 Spotter brushes Burnishing tool (plastic) Etching blade Grumbacher Academy or Windsor Newton Burnt watercolors have been blended: white, Pt/Pd blend, and Umber Watercolor (tube) Pd blend. During the time between spotting sessions, the liquid colors will have returned to a dry, caked form Grumbacher Academy or Windsor Newton Ivory (Figure 10.4). Simply add water before spotting. Black Watercolor (tube) Generally, a brush size larger than one might Spotting lamp (a circular fluorescent tube and anticipate is best. It holds more pigment, allowing magnifying glass combination is best) more control. A good practice is to use the brush almost Watercolor dish dry, with more pigment than appears necessary. The Windsor Newton Dry Ground Titanium White danger in having pigment too thin and wet is that it will (powder) not completely cover the spot but bleed a halo over the (Source: Art Supply) satisfactory print tones. Dip the brush and mark some scratch paper until hardly any pigment remains. Practice It is very difficult to etch or spot black defects on scrap prints. (Platinum printers have lots of those.) caused by negative pinholes or scratches from a platinum and/or palladium print. The coating of a BLACKDEFECTS print extends deeply into the paper, and black defects First examine the print under a magnifying glass that may be equally imbedded. It is best to cover pinholes allows for binocular vision (Figure 10.5). If the defect is and scratches on the negative with retouching material, superficial, it may be possible to flick it off with an such as Crocein Scarlet (Kodak 1463751), before etching blade. If, during this process, the paper nap has printing (see Chapter 3: The Negative). Use the shiny been penetrated, it becomes highly absorbent to side of the negative so that the material will be slightly pigment. Dilute mixtures must be used to restore out of register with the image. It is equally difficult to image tone. cover traces of precipitated metal. If this is a problem, For deeper defects, use Titanium White powder strain the metal salt before coating (see Figure 9.3). mixed with a small amount of distilled water in the Spotting with watercolors in an undiluted form will watercolor tray. A thicker mixture will be used against a match only the whitest and blackest hues of the print. If white background. As the underlying tone approaches it is placed on the midtones, a disagreeable black or light and then mid-gray, add water drop by drop to white spot will form, many times ruining the print. make the pigment more translucent. You will note that if Therefore, one must work from both extremes, black properly mixed, it may appear to be too strong, but it and white, to the midtone areas, diluting with distilled rapidly seeps into the now unsized paper. A heavier water as needed until very little pigment is applied. coating of Titanium White may cause an annoying bulge Work from three wells in the watercolor dish in which on the surface of the print. After it has thoroughly dried, 100 TH€PROC€SS

the light next to the print defect, spot the pad. Check the match through the magnifying glass. Continue through the tonal scales, diluting, until the lightest areas (Zone VII-VIII) are reached. Lastly, spot the defects you have created by etching them or using Titanium White.

THE “BLACKPLAGUE” CURE

Michael Mutmansky has shared his technique for removing those dreaded black spots that sometimes happen in platinum and palladium print^.^ Acid and bleach react together to make PURE CHLORINE. In small quantities, chlorine is fairly harmless, as we know it is used in drinking water, swimming pools, and laundry without any problem. But NEVER mix concentrated bleach and acid together directly! That could result in large quantities of chlorine gas being generated, and is very dangerous. Do not pour the two solutions into a drain at the same time. Better yet, discard them outdoors, away from vegetation. Always work in a well-ventilated area. Do not “improvise” or think that mixing the solution stronger will be of any benefit. Review the safety procedures in Chapter 4: place a piece of glassine over it and lightly rub with a Chemicals. The authors hereby deny liability for any plastic burnishing tool. subsequent injuries resulting from the use of this If the etching or white spotting has been overdone, information. showing a white defect, save the print for spotting of This process requires very small amounts of hydro- white defects. The deeper levels of unsized paper surface chloric (also called muriatic) acid and regular household or Titanium White will both be extremely absorbent. laundry chlorine bleach. Hydrochloric or muriatic acid Use only the most dilute mixture of the dark watercolor. can be purchased at hardware stores and swimming pool supply stores. It is used to clean driveways and WHITE DEFECTS other concrete surfaces. Also needed are two small 1-02 Usually, these defects are easier to handle. First, one (30 ml) bottles. must blend the colors of Burnt Umber and Ivory Black in the watercolor tray with a bit of water to match the 1. Put 20 ml of distilled water in a bottle and add 5 ml print tone. For PdPd prints, start with a 50% portion of hydrochloric acid. Always add acid to water. each. With palladium, use two parts Burnt Umber to one 2. In a separate bottle, add 5 ml of bleach to 20 ml of part Ivory Black. Try the mixtures on old prints until the distilled water. ratio is reached, then record it. 3. Set out a capful of the acid solution and a second Arrange the prints in an order so that those with the capful of the bleach solution. In between the two, defects in the blackest portions are first. Continue to sort place a dish of clean water for rinsing your brush. in order of tones until the defects are in the lightest gray 4. Find a finished print with a black spot. Use a fine, areas. Start at the blackest areas with a barely diluted natural fiber brush and put a small drop of the acid mixture. If, after these are finished, defects remain in lighter areas, place the prints in the stack so that they may be done later with the more dilute solutions. Now, 4. choose the defects in a near-black (Zone 111) area. Dilute This technique is actually the product of a group effort. Richard the mixture in the tray with distilled water until the Sullivan noted a reference to the bleaching properties of hydrochloric acid (HCI)and chlorine in the literature. Michael Mutmansky did the proper concentration is reached. Paint the scratch pad practical tests, and the results were posted by Kevin Sullivan on the until the brush is almost dry. Then, holding the pad under Bostick and Sullivan Web site. solution on the black spot. It won't take much and With all methods of presentation, if glass is to be you don't want the solution to spread farther than used, a mat should be inserted to keep the print from your spot. Rinse the brush in the clean water, then touching the glass. The mat should also be composed of dip the brush in the bleach and lightly touch the archival material-either rag or one of the alpha- bleach to the same area to which you applied the cellulose-treated wood pulp materials. I prefer that the hydrochloric acid. Almost immediately the spot tone of the mat approximate that of the paper used for should start to dissolve away. printing, so as not to detract from the image. Repeat the steps if necessary; each time the spot will As with many printing processes, the portions of the get smaller. Always rinse your brush in between the image to be shown are determined by the artist and, at acid and bleach steps. times, the client (Table 10.3). The more traditional form When done, wash the print again for 10 minutes or of matting has been to stop the mat at the borders of the so to remove leftover chemicals. image. The brush stokes are then covered from view. With some off-white papers, such as Crane's With an image made from an unmasked negative, a Platinotype, the white area of bleaching may show. decision can be made to show the entire effects of the brush This may be corrected by judicious spotting. strokes (Plate 10.4). In this case, the mat would only cover the edges of the print paper. If the negative has been masked during printing, the borders will be that of the P R ES E NTATI o N printing paper and the edge of the mat (Plate 10.3). An effective variation is to allow only a portion of the LIGHTING black border to show (Plate 10.2). Many platinum The delicate hues of the platinum and palladium prints printers allow the margins made by the coating material change with the color temperature of the lighting. The to determine the borders of the print (Plate 10.5). light in the finishing room should approximate the Small Twinrocker Feather Deckle paper can be combined lighting that will be given the framed and displayed with visible brush strokes to present a contiguous image print. Most frequently, some daylight quartz or fluor- (Plate 10.6). escent tubes are desirable. For a little more cost, full As with any art form, there are no rules. If it feels spectrum, color-corrected daylight fluorescent tubes can good, do it. be used in place of the standard, ugly, green hardware bulbs. FRAMING If one prints for exhibition, the galleries must be visited with attention to the intensity of the lighting The choice of frames is a personal matter, generally given to the artwork. For most galleries, the ceiling spots decided by the owner of the print. However, if a framing are more intense than standard room light. Anticipate shop becomes involved, they can be encouraged to avoid that the serious collector will have similar lighting, and the more decorative varieties of frames that may print accordingly. In most cases, the prints will be made overpower the image. darker than what looks good under normal room light. There are a number of choices for glass. The best is Otherwise, they will appear anemic under gallery the rather expensive neutral glass made for artwork lighting. Unfortunately, in the interest of conserving (Image Perfect' and PerfectGlass" ). It does not have the more precarious forms of art, many museums provide greenish tint of ordinary window glass. For most instal- inadequate lighting for photographs. lations, however, the difference between the two is hardly noticeable. Avoid plastic or nonglare glass, as the tones of the print will be veiled. MATTING Most conservators now discourage dry mounting of all NUMBERINGOF EDITIONS artwork. I do not recommend mounting of platinum prints. (Gelatin-sized prints will not stick.) Instead, use Platinudpalladium printing is essentially a print-making the corners available from Light Impressions with process. If Pt/Pd printing represents a new endeavor for archival tape. I also do not recommend waxing, the photographer, this may be the time to begin lacquering, or coating the final print with any substance. numbering and limiting editions. (When I began PtPd (For another opinion regarding waxing, see Appendix printing and editioning, it was too late for me to go back G: Elements of Platinum and Palladium Printing.) and number my silver gelatin prints; there were simply too many in circulation.) The advantages of numbered electromagnetic forces that are not fully understood, editions far outweigh any reasons for objection. a single drop of water will find its way more than 20 An accurate database can identify the location of feet to land on the sky of your negative. any print. In the event of theft, fraud, or loss, the Take care in the selection of negative sleeves. Do not print can be quickly accounted for. use glassine. Light Impressions has a complete Most collectors of art would like to know how collection of archival negative sleeves. many copies have been and will be produced before Keep the complete data with the negative so that they invest in your print. (Just exactly how many reprinting is possible. Record the date, proportions copies of Moonrise are out there?) of metal and Nos. A and B ferric oxalate or Na2 Many artists, the author included, use an escalated concentrations, amount of substances used, light price structure based on edition numbers. As the source (distance), exposure time, paper, and type of number goes up and fewer copies are available, so developer and temperature. I have some preprinted does the price. A collector owning an early edition forms that I use. Never keep these forms in contact number can be comforted by the rising market value. with the negative. I tape them to the outside of the sleeve. Devise some cataloging system that records format, HANDLINGAND STORAGEOF NEGATIVES date and/or chronology, and other pertinent infor- mation. This number can be entered into a database Every photographer has his or her own system for system. negative storage. For the beginner, however, some Store negatives in a dry, cool place, away from suggestions may be in order. environmental hazards. (A garage is not a good Use cotton gloves when handling negatives. Never place.) Consider a fireproof safe or file. Keep leave an uncovered negative in the lab. Due to duplicates at another location. Thispageintentionallyleftblank I3 I..E M s

PLATE 11.1 JuNk14Rd. Ounkn, NEL\Zcnlmd I ,? x 20 INC~Pd

Pride goeth before destruction, and an haughty spirit before LI fall, PRO\ERbS 16 18

105 106 THE PROCESS

Platinum printing is an art wherein a historical process 6. Too Much Moisture in the Brush: If the brush is too is practiced with materials used for purposes for which wet, the coating material is drawn into the bristles they were not intended. The platinum printer must be by capillary action. prepared to deal with failure, and when a solution is 7. The Paper Is Too Damp: Unless an adequate apparently at hand, the Gods will see that you are put amount of solution is used, the coating material may into your proper place. The process is, above all, a be drawn into the deeper paper fibers by the same character builder. capillary action. Humidified paper will take more Every platinum printer I know has a shelf loaded coating solution (see Chapter 10: Advanced with imperfect prints that are not good enough to show, Technique). but too valuable to throw away. As the years go on, 8. The Paper Is Too Dry: Without adequate moisture, the stack becomes higher, and the problems continue. the coating material may not be drawn into the paper fibers. 9. The Paper Surface Is Too Rough: Unless you plan Platinum Printev‘s Prayer to use a lot of solution or double coat, avoid matte Oh Lord, when a product changes, surface or cold pressed papers. in the matter of course, I pray, that only once, it be better, instead of worse.

UNEVENCOATING CHALKYOR ANEMIC PRINTS 1. Inadequate Sizing or Too Little Coating Material: Of all the defective platinudpalladium (PtPd) prints See previous section. that I have viewed, this is the most common problem. 2. Wrong Coating Instrument: As with papers, some Prints made from negatives of insufficient density range of the most elegant (and expensive) brushes are (DR) and/or on paper with inadequate coating have meant for other processes and fail miserably with given many the impression that the Pfld process is platinum. (See Coating Instruments in Chapter 9: characterized by dull and lifeless images. The Platinum and Palladium Print.) 1. Negative Is Not Optimized for PdPd: To get 3. Too Much Brushing: Too much brushing will textured whites and sufficient shadow density, the abrade the paper where there is uneven absorption density range of the negative must match the of the solution. Avoid foam brushes. exposure scale (ES) of the paper. 4. Too Little Brushing: Too little brushing may not 2. Outdated Ferric Oxalate: Old ferric oxalate may allow for even penetration of the solution into the contain a sufficient amount of ferrous oxalate to paper fibers. inhibit the full reduction of the metal salts. This 5. Inadequate Amount of Coating Solution: This is is also the chief cause of fog. a particular problem when using the coating rod. 3. Inadequate Sizing: Without proper sizing, the coat- Make sure that there is enough solution to ing sinks from the surface into the paper fibers. completely cover the image area at the first pass. Of the papers listed in any art supply catalogue, With larger images, there is a chance for the paper the vast majority-particularly those for print to wrinkle, so keep a slightly wetted brush handy making-are not suitable for platinum or palla- to coat the recesses not reached by the rod. dium. Concentrate your experimentation on high- 6. Unsuitable Paper: The paper you select may not quality, hot-pressed watercolor or drawing papers. work if it is too alkaline or has too much carbonate 4. Not Enough Coating Material: This is the most in the sizing. (See Chapter 5: Paper.) common cause for anemic or chalky prints. Take 7. Paper Surface Is Too Slick: Platinum printers particular care when using the coating rod. It is generally prefer a medium vellum surface. Many capable of spreading a quite thin (and inadequate) “plate” finishes repel the coating, forming a useless layer of material. pool at the side of the image area. The same 5. Inadequate Printing Time: This is a most common phenomena would be observed with papers that finding when the light source has not been have been over-sized with gelatin. In that case, calibrated, and the print was simply too far from the many times portions of the image float off in the source to achieve an optimum Dmax for the paper. developer. C RAI N I NESS Metal Salt Precipitant: Unquestionably, this is the most difficult to remove, as it frequently pene- 1. Materials at Too Low a Temperature trates deeply into paper fibers. Do not agitate the 2. Too Much Restrainer (chlorate or dichromate): bottles of metal salts. Filter if necessary. (See the As discussed in Chapter 4: Chemicals, excessive discussions of coating techniques in Chapter 9: amounts of chlorate or dichromate react unevenly The Platinum and Palladium Print.) on the paper fibers, producing a “flocculation,” Some of these defects can be removed by etching which is perceived as grain. the dried print before exposure with a single 3. Too Much Platinum in Relation to Palladium: The edged razor blade, or during spotting. (See platinum metal has more tendencies to produce a Principles of Etching and Spotting Platinum/ granular image than does palladium. The greater Palladium Prints in Chapter 10: Advanced the amount of palladium used in proportion to Technique.) platinum, the smoother the image. Pure palladium will produce the best results. 2. Negative Pinholes: Pinholes are caused by dust in 4. Too Much Work with the Brush: Over-brushing the camera or the film holder during exposure. This causes the paper nap to rise. Use high-quality is particularly annoying in low humidity. Frequently brushes. The cheap ones are too abrasive. Do not dust or vacuum the insides of film holders and use foam brushes. Remember, some papers are cameras. Store holders and camera in plastic or simply unsuitable. Don’t waste time and money Nylon bags. Thoroughly examine the negative on trying to make them work. a light table. Cover the pinholes with Crocein 5. Unsuitable Paper: If your paper is too alkaline or has Scarlet before printing. (See Chapter 10: Advanced too much carbonate in sizing, it will not be useful Technique.) for print making. (See Chapter 5: Paper.) 6. Too Much Ferric Oxalate: Phil Davis has found that too much ferric oxalate in the sensitizer may increase grain. Decreasing the proportion of sensi- STREAKINGBLACKS tizer to metal may also improve granularity as well as warm the tones. This occurs at the border of maximum black and textured white. The black reduced metal will streak onto the white, creating a blurred gray obscuring highlights. BLACKSPOTS ON THE PRINT To help prevent this: (THE “BLACKPLAGUE”) 1. The action of ferrous oxalate to reduce the metal is at its most sensitive at the moment of hydration I know of no other problem that plagues platinum printers as the mysterious appearances of black spots (development). Before putting the print in the (usually in the sky). While the following steps may developer, turn off all the laboratory lights except prevent some spots, they will still appear when least for a small one far from the sink. expected. The bigger ones (1 mm in diameter) are 2. Potassium oxalate developer is close to a super- impossible to spot or etch. The resultant prints are then saturated solution. It is also loaded with reduced metal molecules, which can plate out at the moment added to the drawer “problems.” (See Black Plague in of hydration. As water evaporates, it becomes more Chapter 10: Advanced Technique.) so. Periodically decant the solution and arbitrarily 1. Particulate Matter from Bristles or Coating add distilled water to replace that lost to evapora- Material: To prevent this: tion. This procedure may also help to prevent the “black plague.” Inspect the paper under bright light before coating. If the black dots become a frequent occurrence, change paper stock. Vigorously manipulate the bristles to remove any foreign matter. FOG VERSUSSTAIN Inspect the coating material while it is in the beaker. Particles usually float to the surface and Fog (a light coating of metal where it should not be) are easily removed with a cotton applicator. should be distinguished from staining (unremoved 108 THEPROCESS iron salts). Generally, fogging is uniform and staining first in a solution of EDTA before clearing. In this case, is spotty. Remember that some fogging will most likely subsequent baths of hypo clearing agent may be more occur when no restrainer is used. This is due to minute effective. (See Chapter 5: Paper, for the recommended amounts of reduced ferric oxalate (ferrous) found in clearing agents for each paper.) the freshest of sensitizers. A drop of hydrogen peroxide Residual iron salts may not be visible to the eye. may help (see Appendix A: Chemistry of Developing, Examine the dried print under a blue light to detect Contrast Control, and Clearing Processes), but don’t use stain. it to mask bad sensitizer or poor working conditions. Remember: Fog is archival; stain is most likely not. Fog can be due to too much ultraviolet (W)light in the coating area or too high a concentration of ferrous If a stain occurs that is resistant to any clearing oxalate in your sensitizer. Test this by coating some agents, it may be insoluble iron hydroxide formed either strips in the dark and compare fogging areas to strips in an alkaline developer or clearing bath. (See Appendix done in your normal coating light. If you get fog in both A: Chemistry of Developing, Contrast Control, and strips, the sensitizer is probably bad. Levels of ferrous Clearing Processes). Check the level with pH paper. Add oxalate can also be tested chemically. (See Chapter 4: citric or oxalic acid to bring the developer to an acid state. Chemicals.) If fog occurs only when coated under your Most papers clear adequately in a sulfite/EDTA lighting conditions, there is too much W light. bath. Some of the thicker papers are more resistant. Ferric oxalate is not expensive. Only use analytical Adding sodium bisulfite to the sulfiteEDTA clearing grade from platinum suppliers. Store ferric oxalate in bath will simulate hypo clearing agent and may help. the refrigerator. When in doubt, discard it. If fog A few papers may require an intermediate bath of persists, try a new brush. hydrochloric acid. (See Appendix G: Elements of Some workers who must have consistent, repro- Platinum and Palladium Printing.) ducible results, mix the sensitizer from powder the night before printing. The potassium chlorate restrainer in solution B is also somewhat unstable, causing a reduction in paper contrast and, eventually, fogging. SOLARIZATIONw ITH PALLADIu M Stain is due to uncleared iron salts or ferric oxalate contamination. To avoid this, agitate constantly in This occurs most frequently with insufficient coating the first clearing bath. Make sure fingers or tongs are of pure palladium. It is also found in conditions of low clean before touching the print. (See Clearing Agents relative humidity. Keep the lab at at least 50% humidity. in Chapter 4: Chemicals.) If a problem exists with a (See Humidification of Paper in Chapter 10: Advanced particular paper, the paper fibers could be softened Technique.) 109 KEYSTONE,WEST VlRC,iNiA. 1989 12 X 20 PT/Pd

HiNTonr, Wtsr ViRc,iNin. I989 I2 x 20 Pd CHAPTER 12

LM AND PAPERCURVES

111 1 12 SENSITOMETRY FOR THE PLATINUM/PALLADIUM PROCESS

It is not within the scope of this text to provide the background necessary to achieve a mastery of the sensitometric techniques applicable to the platinum/ Dmin Minimum Density of Materials palladium (Pt/Pd) processes. Therefore, it is necessary IDmin Image Density Minimum that you read the sections on film and paper in the IDmax Image Density Maximum books recommended in the bibliography, particularly Dmax Maximum Density of Materials Phil Davis’ Beyond the Zone System (1998). Better yet, take a BTZS (Beyond the Zone System) workshop. They are scheduled through the View Camera Store. (See Sources.) TABLE 12.1 B TERMINO~O~YfOR MAXIMUM ANd MINIMUM DtNSiTy VAlLIES Before we can add information to the concepts fOR PAPER ANd TkE NEqATiVt discussed in the Chapter 3: The Negative, we must Negative Transmission understand the essentials of plotting, on a graph, the Paper Reflective Density Density characteristics of how film and paper react to light. For the study of film, transmission densities are read Paper White Dmin Base + Fog Dmin following exposure to a step tablet. With paper, Threshold of IDmin Threshold of IDmin reflective densities are read from an exposure to the Textured White Textured Shadow same step tablet. By these methods, the properties Threshold of IDmax Threshold of IDmax of both materials can be analyzed. In each case, the Textured Textured Highlight amounts of light directed to the material are plotted, Black (90%) Maximum Dmax from left to right in increasing increments, on the Paper Black horizontal or “x” axis. The increases in density of either film or paper are plotted on the vertical, or “y” axis. (Look ahead to Figure 13.1.) If the density of materials increased in direct (Table 12.1). Note that both paper and negatives have proportion to the light, the registration of data would extremes of density that are not normally used in the form a straight line. This is not the case. The uneven planning of an image. These are referred to as Dmin and behavior of metal salts does not produce a straight line Dmax. More important are the limits for textured but rather a characteristic curve-one that elevates from values. These are called the image densities, IDmin and left to right in response to the increase in light.’ IDmax. Since the vast majority of readers have some experience with silver printing, I will provide the essentials of that process so that they may be compared THE INDIVIDUALSILVER CURVE later to platinum and palladium printing. The value of light reflected from paper is measured by reading reflective densities. In analyzing an individual silver curve (Figure 12.1), one will see that it is indeed S I LVE R AN D PLATIN u M/ PALLADI u M not a straight bar, but shows disproportionate response CURVESCOMPARED to light, particularly in the shadow and highlight areas.

The curves presented are courtesy of Phil Davis Plotter 1. The highlight areas are represented closest to the Program‘. x axis. The 0.0 marker on the y axis represents Other sources on the subject of sensitometry may paper white (Dmin).A horizontal line drawn just use different designations in describing reference points above the base indicates minimum image density on the paper and film graphs. Since the graphics for (IDmin),‘ the level at which paper begins to respond this text were derived from the Plotter ProgramE’, I will to light. In this case, it is 0.04. Note that on the left, present the terminology programmed into that software

’. The 0.0 setting here is based on the paper white. This representation Photographic processes that do not rely on the reduction of metal will vary according to the white of the paper stock. Many silver gelatin salts produce a straight-line response to increases in light. This would papers contain a whitening agent that further lightens this value. include carbon printing, as well as the various methods creating Papers used for platinum do not. The irnportant point is to understand a bas-relief as a reservoir to hold ink, such as gravure. In the digital that IDinin is the beginning of textitred white for a particular paper. realm, any curve is possible, including a straight line. (See Tables 12.1A and 12.1B.) Oriental Seagull #2 Cond. Projector 2.4 D-72 diluted 1:2

IDrnax = 1.84

DR=1.8

IDrnin = 0.04

30 27 2.4 2.1 1.8 15 12 0.9 0.6 0.3 0.0 Emin =2.17 ES = 0.96 Ernax = 1.21

initially there is little movement when the paper density (or IDmax) of 1.84, showing that silver reaches its “threshold.” However, once activated, gelatin paper is capable of reaching one of the this toe portion at the lower left of the graph deepest blacks seen in any medium. elevates very abruptly, indicating at IDmin a rapid 5. Observe that the entire silver curve is steep. There is change from blank white to texture, leaving little considerable increase in paper density in response to latitude for representation of whites. In Figure 12.1, very little change in light. The negative, therefore, note the beginning of texture in the white areas of must be of low contrast. One can see, at the base, the “Paper Range and Densities” bar. the range of light responsible for the full-range silver 2. The middle portion of the graph is quite straight, print: the exposure scale (ES). Since the light was indicating an even response to increases in light, and provided to the film by way of a step tablet, the good separation in the midtones of a silver print. numbers along the x axis represent step tablet 3. The upper portion, or shoulder, also shows a transmission densities. This particular ES indicates sluggish response to light increase. This poor the need for a photographic negative with a density separation in the area of maximum blacks is range of 0.96, corrected to 0.95? seen with monochromatic photographic papers, platinum or palladium included. Note the blockage of black tones represented in the “Paper Range and THE NEGATIVEFOR SILVERPAPER Densities” bar in Figure 12.1. This characteristic has As I indicated in Chapter 3: The Negative, the transfer prompted the American National Standard Institute of information from the subject to photographic paper (ANSI), to eliminate the maximum 10% of black in necessitates considerable compression of the density the standardization of photographic paper. This range (DR) of the negative. Note in Figure 12.2 that leaves an approximately 90% range between although the subject brightness range (SBR) of the perceptible white (IDmin) and 90% black (IDmax). object photographed is 6.5, the DR of the negative This is obviously not a hard and fast rule; it is is considerably less. This is represented in the “Negative simply a tool for paper calibration. The photo- Range and Densities” bar. To calculate the useful values grapher can use this knowledge to deviate from the of a negative, the effective shadow density is obtained norm, if so desired. (See the discussion of convincing black in Chapter 3: The Negative and Chapter 8: Calibration.) 3. With the understanding that the photographic process need not be 4. Note that even with the elimination of the 10% practiced to impractical tolerances, we round off all density readings blackest portion, the 90% black is at a reflective to the nearest 0.05. 1 14 SENSITOMETRY FOR THE PLATINUM/PALLADIUM PROCESS

Film: TXT Curve # 3 Developer: D-76 Speed Point Location: GI9 2.1 Dilution: 1:l Average Gradient. 0.48 Dev. for 9 rnins. @ 70’F SBR: 6.5 1.8

3.0 2.7 2.4 2.1 1.8 1.5 1.2 0.9 0.6 0.3 0.0

Emin - 2.38 LogE - 1.96 Emax - 0.42

by adding the base + fog (B+ F) and lens flare (Dmin) SBR of light. This, in practical terms, is translated to to the density at which the curve begins an effective rise. negative contrast. A number of methods are used to The point at which effective shadow density begins is measure the steepness of the curve. Here, it is the IDmin (see Table 12.1). average gradient. Note that in Figure 12.2 it is 0.48 For highlights, modern film has essentially no limit (Kodak, 1998). of Dmax, since most films will continue the projection upward off to beyond the confines of the graph. The point, however, where effective highlights end is termed IDrnax. In Figure 12.2, this is the dark edge of the T H E I ND I v I DUAL PLATI NUM/ PALLAD Iu M C u RV E “Negative Range and Densities” bar. In examining a PdPd paper curve, note that the To further interpret Figure 12.2, The film B+F of terminology is the same. Variations in the numbers 0.06 is added to the density (0.16) at which the curve and graphic representations, however, can be used to begins an effective rise. The total is 0.22. This number, note the characteristics of Pt/Pd paper. which can be easily read by a transmission densitometer, A mixture of six drops of A (27% ferric oxalate) and is the threshold of shadow detail, or the IDmin for this six drops of B (27% ferric oxalate and 0.6% potassium filddeveloper combination. This is seen as the begin- chlorate) will produce a medium contrast. PtPd curve ning of texture at the lower end of the “Negative Range (Figure 12.3). An identical medium contrast curve can and Densities” bar. IDmin is subtracted from the be observed with a No. 5s mixture of palladium with IDmax of 1.17 (the threshold of textured highlight) to Na2. In examining a Pt/Pd curve (Figure 12.3), note the give a DR of 0.95. This negative has, therefore, been following: constructed to print on a paper with an ES of 0.95, a little over three stops. In this case, D-76 was used at The paper curves illustrated in this chapter were a 1:1 dilution. generated from PdPd and Pd mixtures using the Ratio (A + B) Method of contrast control. When appropriate, STEEPNESSOF THE CURVE I will refer to the comparable mixtures using the Na2 Method. As in the previous chapters, I will use italics to The steepness of the film curve determines the amount indicate that method. of transmission density the negative will acquire in response to increases in light. As the steepness of the In the toe portion of the graph, the transition film curve increases, more DR is formed for a given through the values of textured white is gradual, 2.1

1.8

1.5

IDrnax = 1.35 1.2

0.9

DR = 1.29 0.6

0.3

IDrnin = 0.06

30 27 24 21 18 15 12 09 06 03 00 Ernin = 1 98 ES=142 Emax = 0 56

FIGURE 12.3 A CURVE fOR A MEdlUM-CONTRAST PlATlNUM/PALLAdlUM MIXT~IREWkEN COMPAREd TO TkE 5llVER PAPtR CURL€. NOTE TkE LOWER IDWZUX ON ThE ”PAPER RANGEANd DENSITIES”bAR ANd TkE GREATER EXpO5URE SCALE ON lkt kORlZONTAl AXIS

allowing for great subtlety in the rendition of D-76 was used undiluted. Note that the average whites4 gradient is 0.72. With an SBR of 6.5, the steepness The gradation of midtones is uniform. These last of the curve now shows an IDmax of 1.66. When two characteristics help produce the typical the IDiniiz of 0.25 is subtracted from the IDmax, a platinum print appearance. DR of 1.41 (1.40) is obtained. Note the comparative As with silver paper, the leveling at the shoulder range of densities between the “Negative Range and indicates that black separation is poor when close Densities” bars for silver and PtPd (see Figures 12.2 to maximum, thus the need for ANSI specifica- and 12.4). tions of 90% black. The blacks are not nearly as intense: a 1.50 maximum black reflective density (Dmax)com- pared to a 2.0 silver Dmax. The IDmax is 1.35 CONTRASTCONTROL compared to an IDmax of 1.84 for silver. (Remember, convincing black.) Not all negatives will fall into the “ideal” 1.4 DR. There is a wider spread of ES, indicating Also, a desired interpretation may call for a negative of that a negative of a density range of 1.4 is less or more than that which would produce a full tonal needed for a print exhibiting a full tonal scale. value print. Paper contrast control is possible by adjusting the amount of restrainer (oxidizer) using the various methods of contrast control. (See Chapter 7: Choose your Method.) THE NEGATIVEFOR A PLATINUM/PALLADIUMPRINT The PtPd negative must be processed with consider- ably more energy than one for silver. In Figure 12.4, A PLATINUM/PALLADIUMcuRvE FOR A HIGHLONTRASTNEGATIVE If one uses a No. 2 mixture (12 parts A and 1 part B) to approximate maximum PtPd paper latitude (Nu2 4. The characteristics of the Pt/Pd and Pd paper toes will be discussed at length in this chapter. Of all the attributes of this process, I consider No. 2s)~a negative with a DR of l.7 can now be used the extended toe to be the most unique. to match the paper ES of 1.7 (Figure 12.5). Remember, 1 16 9 SENSITOMETRY FOR THE PLATINUM/PALLADIUM PROCESS

24

21

18

15 P5 B 12 m

09 Pf

06 n2

03 s rrc!? I B+F = Dmin 0.17 - 0.0 w 3.0 2.7 2.4 2.1 1.8 1.5 1.2 0.9 0.6 0.3 0.0 Emin . 2.19 Log€ - 1.95 Emax - 0.24

Cranes Parchment WPd No. 2 nuArc Brush 2.4 KOX 9O'F Average Gradient: 0.75 IS0 Range: 1.70 21

1.8

1.5

~ IDmax = 1.35 1.2

0.9

o.6 DR = 1.28

0.3

~ I o,o IDmin = 0.07

3.0 2.7 24 2.1 1.8 1.5 12 0.9 06 0.3 0.0 Emin = 2.32 ES=1.71 Emax = 0.61

a straight A mixture will likely fog. Note the accentuated sufficiently above the reflective density of paper white to toe at this contrast mixture. be annoying in many images. Because of the effect of fog, only an ES of 1.75 could be reached.

EFFECTOF FOG A PLATINUM/PALLADIUMCURVE FOR When ferric oxalate solution A is used alone with the A LOWXONTRASTNEGATIVE metal salts, no restrainer is incorporated in the mixture (Figure 1216). While the Dmin of 0.10 may appear to A negative with a DR of 1.0 to 1.1 represents the least be infinitesimal, it is readily visible to the eye. It is usable contrast for the contrast mixtures typically :ranes Parchment PVPd No. 1 iuArc Brush 2.4 COX 9O~F 4verage Gradient: 0.73 SO Range. 1.80 2.1

1.a

1.5 -IDmax = 1.37

1.2

0.9

o,6 DR= 1.27

0.3

- IDrnin = 0.10 0.0

30 27 24 21 18 15 12 09 06 03 00 Emin = 2 40 ES=175 Emax = 0 65

Cranes Parchment WPd No. 11 nuArc BNsh 2.4 KOX 9O~F Average Gradient: 1.I8 IS0 Range 1.I 0 2.1

1.8

1.5 -IDmax = 1.35 1.2

0.9

o.6 DR = 1.29 I Speed Point

0.3

-o.o IDrnin =006

3.0 2.7 2.4 2 1 1.8 15 1.2 0.9 0.6 0.3 0.0 Emin = 1.58 ES = 1.09 Emax = 0.49

FIGURE 12.7 A PlAllNUFvl/PAllAdIUM NFGATiVF fOR A LO\*-CONTRA5T NEGATIVE

employed. Figure 12.7 represents a mixture of all I\( )I I Although a satisfactory print can be made from ferric oxalate B (Na2 No. 8s). In this case, a negative a negative of low DR by using a high-contrast mixture with a density range of 1.09 (1.1) is indicated. When containing more oxidizer, the image will not be the same using the Ratio Method, because of the amount as one from a high DR negative and a contrast mixture of chlorate used, there will be an increase in printing containing a minimal amount of oxidizer. When the time, as well as granularity. With the Na2 mixture ES of the print is compressed to accommodate a thin No. 8s, the identical curve can be observed, but the negative, it occurs most prominently in the toe section amount of granularity in the print will be greatly of the curve. Conversely, a print made with a high ES to reduced. fit a contrasty negative will exhibit the attributes of an 1 18 8 SENSITOMETRY FOR THE PLATINUM/PALLADIUM PROCESS

Cranes Parchment PtJPd No. 13+ nuArc Brush 2.4 I KOX 9O'F Average Gradient: 1.33 IS0 Range: 1 .XI 2.1

1.8

1.5

IDmax = 1.35 1.2

0.9

Speed Point o,6 DR = 1.29

03 I 4 IDrnin=0.06

3.0 2.7 2.4 2 1 1.8 1.5 1.2 09 0.6 0.3 0.0 Emin = 1 .A6 ES = 0.97 Emax = 0.49

FIGURE 12.8 A PlATiNUM/P4llAdIUM CURVENO. 13+ ObTAlNEd WTk FERRIC OXA~ATFSO~UTION B CONTAININq DOU~~EThE CONCENTRATION Of POTA55iUM CklORATE ( 1 .2% iPjSTEAd Of 0.6%). NOTETkE RE~FM~IANCETO FiquRE 12. 1, A TypicAl SILVER CLRVE. 6OTk CKRVES Exkibir AN EXTREMEIV SkORlENEd TOE extended toe. (See upcoming section: Let There be Light, When the resultant curves are plotted simultaneously, on the subject of the expansion of the Zone VII through a family of curves is obtained (Figure 12.9). When IX areas.) these are analyzed, it can be found that for PtPd paper, exposure scales from 1.1 to 1.7 can be obtained. (See Chapter 13: Using the Print Curves.) Using these WHENTHE NEGATIVEHAS INADEOUATE CONTRAST methods, the changes in printing speed related to the amount of restrainer used can also be calculated. When the DR of a negative is still inadequate, even Read on! after intensification, such as with selenium toning, it is possible to further shorten the paper scale by an increment of 0.1 to 0.15 by doubling the amount of potassium chlorate in the sensitizer from 0.6% to THE PALLADIUMPRINT 1.2%. We refer to this contrast mixture as 13+, since it exceeds the No. 13 contrast grade introduced THE FAMILIESOF PALLADIUMCURVES in Chapter 8: Calibration. The resultant granularity will be further exaggerated. Note that the ES is now THE FAMILYOF PALLADIUMCURVES USING THE RATIOMETHOD 0.97 (0.95) (Figure 12.8). A comparable curve can be When comparing the Family of Curves produced by generated by using extreme mixtures of Na2 (four pure palladium to that of Pt/Pd (Figure 12.10), some drops of 20% Na2 and 12 drops of palladium and of the features discussed in Chapter 1: Platinum and ferric oxalate.) Compared to the Ratio Method's Palladium, can be visualized. No. 13+, granularity will be greatly reduced. With Note that although the vertical placements are either method, as a result of the extreme shortening approximately the same as Pt/Pd, the Pd curves are of the paper ES, the curve will begin to resemble that spread over a greater horizontal distance, indicating of a silver gelatin print. the need for a negative of even greater density range. The toe portions indicate a more gradual elevation than with Pt/Pd. Translated to practical terms, we see THE FAMILYOF PLATINUM/PALLADIUMCURVES that with palladium, the distribution of textured whites By adjusting the amounts of ferric oxalate solutions A is more broadly dispersed. and B, 13 paper grades can be obtained. (See Standard The tests for the family of palladium curves were Negative Contrast Ranges in Chapter 8: Calibration.) done using ferric oxalate B containing the same 0.6% I I I It

THE FAMILY OF PALLADIUMCURVES USING THE NA2 METHOD Compare the palladium family of curves using Na2 to Figures 12.9 and 12.10. Note that, while there are only eight curves, they cover the exposure scales of both the PtPd and Pd families using chlorate as a restrainer.

THE CHARACTERISTICSOF PALLADIUM CURVES

We will now return to the palladium curves generated FIGURE 12.1 I A FAMILY Of PAllAdlUM CURVES USIN4 TkF by using the Ratio (A + B) Method. As will be seen, they NA~Mtrkod. are characterized by having a long toe. As the amount of restrainer is decreased to accommodate negatives of greater ES, the toe proportion increases until it concentration of potassium chlorate as with the Pt/Pd becomes a major portion of the tonal scale. curves. 5 Note also in Table 7.1 that the shortest ES is 1.3. While it is possible to reach 1.1 by using ferric oxalate A PALLADIUMCURVE FOR A NORMAL. with 1.2% of potassium chlorate (Bostick and Sullivan CONTRASTNEGATIVE [BS] sensitizer No. 2 Pd), the resultant granularity makes it a poor choice. The same effect can be achieved with For more information we can analyze a single curve the use of Na2. produced by a mixture of 50% each of ferric oxalate A and B, with an equal amount of palladium salt (Figure 12.12). Note the gradual toe. Note that the same '. Bostick and Sullivan market a special sensitizer B (No. 2 Pd) with No. 7 mixture calling for equal proportions of ferric double the restrainer (1.2%)for use with palladium. With this, the exposure scales approximate those of Pt/Pd used with the 0.6% (No. 2 Pt). oxalate A and B produced an ES is 1.59 (1.60) with When printing with pure palladium, however, I prefer to USK the ferric pure palladium. Compare this to the 1.4 ES found with oxalate B with 0.6% restrainer. With the resultant expansion of the a similar mixture for Pt/Pd (see Figure 12.3). Therefore, exposure scale, a more contrasty negative can be used. A longer scale the construction of an "ideal" negative for a middle negative allows a ferric oxalate mixture containing less restrainer to be "Grade 2" contrast mixture depends also upon the utilized, resulting in a print of smoother tones. The toe is accentuated to the point where the textured whites continue for several stops of exposure. combination of metal salts to be used. Additionally, to a These properties, added to the exquisite hue of the pure palladium print, lesser extent, the type of paper and developer must be make it unique among the photographic printing processes. factored in. 120 SENSITOMETRY FOR THE PLATINUM/PALLADIUM PROCESS

Cranes Parchment Pd No. 7 nuArc BNsh 2.4 KOX 9OF Averaae Gradient: 0.80 IS0 Range: 1 60 2.1

1.8

1.5

-IDmax = 1.33 1.2

0.9

o6 DR= 1.25

0.3

0.0 IDmin = 0 08

3.0 2.7 2.4 2.1 1.8 15 12 0.9 0.6 0.3 0.C Emin = 2.21 ES=1.59 Emax = 0.65

FIGURE 12.1 2 A PAllAdluM CURLIfon A NORMALCONTRAST NEGATIVE FERRIC OXA~ATE B wirk 0 6% ~OTASSIUMC~~ORATE WAS usEd

A PALLADIUMCURVE FOR A HIGHXONTRASTNEGATIVE be transmitted to monochrome, others will suffer in the translation when conveyed to a flattened surface Figure 12.13 demonstrates, graphically, the remarkable devoid of color. For example, what appear to be properties of a pure palladium print when minute vivid shadows will many times become “mud” in the amounts of oxidizer are used. Note particularly the print. When printing in either silver or PtPd, we take rise of the curve from the toe to the mid-portion. This into account the inability of either process to separate may easily be visualized as print tones undergoing an low tones. Therefore, when metering, we these almost endless transition from barely textured white to values well into the Zone 111 range, avoiding the Zone I1 the upper midtones of the print. It is from negatives such shoulder of the paper curve. as these that the uniqueness of the palladium printing It is in the metering of highlights that silver and process is unsurpassed. Pt/Pd differ in a remarkable fashion. In previsualization with the Zone System, silver photographers generally avoid placing the brightest areas above Zone VII knowing, unless particular techniques are used in the LET THERE BE LIGHT development of the negative, the silver paper will not In Chapter 1: Platinum and Palladium, I made reference be able to retain any textured values beyond this. Some to the importance of learning to “see” in a particular learn to avoid the harsh lighting of mid day and prefer medium. I also mentioned some of the attributes of to work in the soft light of morning and evening. the Pt/Pd print that make it a unique art form. I have When printing with Pt/Pd and pure palladium, also discussed, throughout this book, the properties of the opposite may be the case. Palladium photographers the extended toe of a palladium print. Now, I would particularly learn to meter and plan images well into like to delve into this remarkable characteristic in more the Zone VIII range and, because of the extended toe, depth. well into Zone IX and X! (See Plate 12.2.) We are indeed During the process of previsualization as taught photographing the essence of light! by Ansel Adams and Minor White, a three dimensional color entity is transformed in the brain to an image on a flat surface, and in many cases, to shades of mono- 6. In Zone System photography, one chooses a light value when chromatic tones. (See Chapter 3: The Negative.) One metering a subject (usually Zone 111) and places it in a segment of the grayscale. Other values (Zones) will “fall” and be distributed in the learns by practicing the Zone System that while many print based on the type of negative development, printing materials, shapes of different colors and lighting can effectively and technique (Davis, 1998; Schaefer, 1998). :ranes Parchment Pd No. 2 iuArc Brush 2.4

1.8

1.5

-IDmax = 1.24 Speed Point 1.2

0.9

o6 DR= 1.26

0.3 I -o.o IDmin = 0.08 I 3 0 2 7 2.4 2.1 1.8 1 5 1.2 0.9 0.6 0 3 0 0 Emin = 2.63 ES=1.91 Emax = 0.72

THE MATCHERPROGRAM@ In examining the Matcher illustrations, Figures The Matcher Program’&’is part of the Plotter Program’” 12.14 and 12.15, the Zone values at the x axis are the used to create the film and paper curves in Part Two light values that have been compressed into a negative of this text. By “matching” a film curve to a particular suitable for silver and palladium printing (see Figures paper, the reflective values that were metered and 3.2 and 3.3). The density ranges of the negatives demon- assigned to different Zones are projected to the reflective strated here are 1.00 (silver) and 1.91 (palladium). The tones of the print (Figures 12.14 and 12.15). y axis shows the reflective densities of the print made 122 SENSITOMETRY FOR THE PLATINUM/PALLADIUM PROCESS from that particular negative. The vertical column to the and particularly VII are severely compressed in far right (Ref) shows the print values that one might the print. expect if the light transmitted through the negative was These observations are not meant to be critical of distributed evenly in a “reference” print. The adjacent the silver print. As I stated in Chapter 1: Platinum and vertical column (Print) shows the actual distribution of Palladium, the silver gelatin print is and will remain the reflective densities for the particular paper entered into most popular monochromatic medium in photography. the program. The Matcher file shows not the deficiencies of the silver print, but its characteristics, which master photogra- THE SILVER GELATIN PRINT phers over the years have used to great advantage. This In Figure 12.14, note the following: mastery is, in part, based on the selection of imagery appropriate to the medium. 1. In the horizontal bar, the metered Zones I1 to VIII have been compressed into a negative with a DR of 1.00. This is to accommodate the exposure scale THE PALLADIUM PRINT of the Grade 2 silver paper. In Figure 12.15, note the following: 2. The Zone values have been projected upward to 1. In the horizontal bar the metered Zones I1 to VII are intersect a typical silver paper curve. Note that their not nearly as compressed. They show a DR of 1.91, values have then been projected to the right to for palladium Contrast Mixture No. 2. indicate where they will be transformed to the 2. As with Figure 12.14, the Zone values have been grayscale of the paper. projected upward, this time intersecting a low 3. The heights of the vertical bars represent the contrast palladium paper curve. Note that, when reflective values of the print. In the case of a silver compared to the silver curve, the palladium curve print, one can expect a reflective density range of encompasses a broader input of Zones, but is 1.9 to 2.1. In this case it is 2.00. projected to the right to show only a 1.23 IDmax 4. The vertical Reference bar (Ref) shows the reflective density and a 1.19 paper DR. This is shown characteristics expected from a typical silver in the truncated heights of the vertical bars (consi- gelatin print. The Print bar (Print) shows the derably less than the 2.00 DR of the silver print). print values obtained by this specific film curve 3. When compared to the Reference bar, the Print bar and paper. Note that the Zones I1 to IV shows that Zones I1 to IV have been compressed, have been expanded and the Zones VI to VII while the Zones VI to VII have been expanded. This have been compressed. This is typical for most is a function of the palladium toe. silver papers. 4. The 18% reflective gray, when projected horizon- 5. A Zone V value, when printed on paper, is usually tally to the paper tested, falls in the Zone V and VI defined as an 18% reflective gray. Note that when areas. As opposed to the minimal development a Zone V is projected horizontally from the silver needed for a silver print negative, the palladium paper curve to the paper tested, it falls between negative is usually “cooked” to maximum Zones IV and V, well below an 18% gray. This is development, raising all the Zones proportionately a common finding due the extreme compression from the base Zone 111. (See Appendix C: Some of negative transmission densities needed to match FilmDeveloper Combinations.) Beginning at the the ES of a silver paper. When an accurate Zone V to VI areas, and with subsequent expansion representation of Zone V is desired, the metered of Zones VII to IX, the palladium print will take on Zone V can be placed at that level, allowing the the sensation of luminosity. Zone I11 shadows to full, depending on development 5. Metering for a palladium print is quite different of the negative. than for silver. The Zones VI to VIII will have added 6. Most light meters will give EV readings wherein prominence in the planning of an image. each reflective value is uniformly registered, only 6. Note in Figure 12.15 that a Zone IX can be added slightly modified by color. Therefore, if assigned as part of the image,’ knowing that, while not to Zones, each will be of equal “size.” (Because of the difficulty of low light reading, the margins ’. ANSI has defined the beginning of a paper toe at 0.04 above paper of Zones I1 and I11 are frequently blurred.) Note, white. This is too high for palladlum. Although it may not be however, that although the Zones are equally measurable with a machine, the visible palladium toe goes at least spaced on the horizontal bar, Zones VI, VII, 1/2 to a full stop (0.15 to 0.30) beyond this. 2.4

on P RR If Nf T

12

P I 19 I n I - -1- - - - - 36 I DR='.19 D /; R

13 0 9 9

on PR

technically part of a film curve, it will appear, COMBINING THE MATCHERFILES particularly after dry down of the wet print. In some By flipping the Matcher file for Grade 2 silver paper cases, as shown in Plates 12.3 and 12.4, the flair and placing it adjacent to the palladium file, the two from intense sun can be included as a Zone X!This illustrations can be directly compared (Figure 12.16). phenomenon is equally advantageous with all Here, the relative reflective densities of the two papers extremes of lighting (as with window light in an are graphically displayed side by side. While the Pd interior space). paper conveys the lighter tones, well into Zones VI to 124 SENSITOMETRY FOR THE PLATINUM/PALLADIUM PROCESS

IX, the silver paper accentuates the darker tones of the goal, allowing for a slim margin of error in Zones 111 to V. Add to this the intense black obtainable overdeveloping. with silver paper. They are indeed two distinct visual media. As discussed, when working with palladium contrast mixtures Nos. 1, 2, or 3, the effect of the potassium chlorate used is negligible. Therefore, I would NEGATIVEDEVELOPMENT FOR THE LONGTOE recommend the Ratio (A+B) Method. The palladium examples shown require a negative of considerable density range (1.80-2.00). Any DR beyond In Appendix C: Some Film/Developer Combina- this (2.1+), cannot be printed to a full tonal value on tions, I give recommended development times for various any palladium contrast mixture. Therefore, in planning filddeveloper combinations. Also, times are given for for a 1.9 negative, there is little room for error in negatives of 1.40, 1.60, and 1.80 density ranges. I have development. In the earlier portions of this text, found that if one wishes to work at the “edge” for a 1.80 I recommended a negative DR of 1.40 for PdPd and negative, expose at least two sheets of film identically. 1.60 for Pd. These “mid points” allow for considerable Develop only one, and read its density so minor changes error in either underdeveloping or overdeveloping. can be made to the second if necessary. I describe my However, if one wishes to maximize the effect of the method of sorting film for development in Appendix B: palladium toe, a negative DR of at least 1.8 should be The Large Negative. Paper Test: Ilford Galerie 2 Paper Test: ES .95 Pd Curve No. 2 D-I2 1:2 Cranes Platinotype 4 nuArc Brush ES 1.90 KOX IOOirF 5:45 tnins TMax RS :4 Film Test G = .61 SBR = 5.I TMY

8 rnm D-76 1 1 G= 55 SBR=11.5

VI VII Vlll I - 0.0 0.3 0.6 0. I 1.7 Ill.71.7 ll.f31I1.r I 2.1 2.4 2.7 -3.0 3.0 2.7 2.4 2.1 1.8 1.5 12 0.9 0.6 03 0.0 111 IV v VI VIIVlll tlX I Vlll IVII I VI I v I IV I111I II I

FIGURE 12.16 MATtkER"PROGRAMS CCJM~ARIN~ PAPERScAlFS of NO 2 CONTRASTMIXTURE PAllAdlUM ANd GRAdE2 SILVERPAPER Thispageintentionallyleftblank CHAPTER 13

USING THE CURVE.S

PLATE 13.1 OR~ANPipF CACIUS, Diablo MOUNTAINS. AR~ZONA.2001 12 X 'Lo INCk Pd. ThE SONORAN dESERT kAs A pARTiCUlAR SkiMMERiN4 QUAllTy IN &INTER MORNINGS This IIGhTiNc, CAN br CApTUREd EXQUiSiTElL ON A pAllAdiUM pRiNT WkiLE ThE LOWER TONES ARE krpT NATURAL bv NFAR NORMA1 PAPER CONTRAST, TkE pdhdiuM TOE AllO!NS ThE AMbiENT kic,kliqhrs TO REACk WE" INTO ZONES vlll ANd Ix.

127 128 SENSITOMETRY FOR THE PLATINUM/PALLADIUM PROCESS

In choosing the contrast mixture for a particular densitometer' and matched to a known shadow density negative, many platinum and palladium printers use that produced it, we can use this standard to calculate guides similar to those presented in the Standard printing times for those negatives where the shadow Negative Contrast Ranges provided in Chapter 7: readings match that standard. For negatives where the Choosing Your Method. They may analyze a concur- shadow values deviate to less or more than that rently printed step tablet or simply resort to trial and standard, further calculations are possible to determine error. It is, however, possible to customize your own printing time. work, incorporating your coating technique, paper, light When calibrating the light source, a standard was source, and developer. approximated using a 50% (No. 7) mixture of ferric While the curves generated by the Plotter ProgramR oxalate A and B with a particular metal salt combina- (see Chapter 12: The Film and Paper Curves) are tion at an exposure of 10 minutes or 400 units with illuminating, more useful information can be obtained a NuArc. That standard should now be assessed with from a detailed analysis of the information provided more accuracy. Much of the reference material in this in a graphic representation of platinum and palladium chapter will be based on the Ratio (A + B) Method with paper characteristics. In the earlier portions of this a 50% mixture of platinum and palladium. If you are text, I showed that a reflection densitometer was not using the Na2 method, start with mixture No. Ss. necessary for basic calibration. At this point, one will See ahead to Figure 13.3 for more specific information be of value. However, once your technique is fine-tuned, and an Na2 family of Palladium curves. it will no longer be needed. So, unless you intend to extensively study these matters, it is best to arrange For assistance in these exercises, refer to the for the temporary use of a reflection densitometer by depiction of step tablet values in Calibrating the Light borrowing or renting (a print shop is a good source). Source in Chapter 8: Calibration. At the time of publication, used ones have been available During the light source calibration, it was recom- on eBay (www.ebay.com). mended that 90% black should be produced by the Nr. 5' (0.65 density) step of the tablet. Now, this should become a requirement. Using the reflection densitometer or the information REFININGTHE STANDARDS presented in Chapter 8: Calibration, the light-to-print When compared to the standard enlargement procedure distance for a No. 7 contrast mixture at 10 minutes used in the printing of silver paper, contact printing (400 units), should now be accurately stabilized to from a set light source allows the elimination of two produce a 90% black on the Nr. S step. variables. The distance of the light source to the paper 1. The making of a No. 7 contrast mixture printed step (the height of the enlarger head) and the aperture of tablet has been described in Chapter 8: Calibration. the enlarging lens do not need to be factored into any (see Figure 8.6). Read the area of maximum black data used in calibration. (Dmax).It should be at the step Nr. 1 or the Since the light intensity is constant, the only issues surrounding area. That reflective density should fall we must consider are the shadow values and contrast mixture.

'. From numerous workshops, using varied light sources, 1 have found SHADOWVALUES that the Stizndird Negatizv Contrast Ranges and the Families of Curves shown in the book are quite accurate. Therefore, it is possible The time of paper exposure is determined by the to use the published data rather than draw your own curves. In this transmission density of the Zone 111 textured shadow event, a reflection densitometer may not be entirely necessary. To use the information presented in this chapter, the 90% black should be in areas of the negative. In making the print, these values the Nr. 5 step of a step tablet. To locate the 90% black on your test are translated to the darkest portions of the image. prints, refer to Figure 8.6 in Chapter 8: Calibration. Adjust the light We now understand that these are arbitrarily defined source until Step Nrs. 1 to 3 merge. If a slightly discernible change at 90% of maximum paper black. During the analysis is noted in Step Nr. 4, Step Nr. 5 should represent a 90% black. of the step tablet prints in Chapter 8: Calibration, we '. Numbers will be used in reference to both step tablet numbers and contrast mixture numbers. For clarity, the European abbreviation (Nr.) identified those values by the eye. Now, with 90% will be used for step tablet numbers and the English (No.) for the increment values accurately determined by a reflection contrast mixture. ~~

in the 1.40 to 1.50 range.3 If the coating is not time. This can be observed in the step tablet prints in sufficient, another print of the step tablet must be Calibrating the Light Source in Chapter 8: Calibration made. It is at this point that the brush and coating (see Figures 8.7 through 8.11). rod could be compared, as well as your coating If the strips were coated well and laid in order from technique. An anemic coating will lead to weak No. l5to No. 13, the 90% black step will move relative reflective values and mottling of the image. to the contrast mixture, thus indicating changes in 2. Multiply the Dmax value by 0.9. For example, printing speed. 1.50 x 0.9 = 1.35. A reflective density of 1.35 In the strip made from the No. 2 mixture, the 90% (IDmax) will be the 90% “convincing black” of black will have occurred at a higher number panel than your prints. the strip made with the No. 7 mixture (see Figure 8.9). 3. Using the reflection densitometer,’ find the tablet If the No. 7 strip indicated a 90% black at Nr. 5 (0.60 number on the print that most closely approximates transmission density), the same value on the No. 2 strip this number. Make minor adjustments in the light- might occur on step Nr. 6 with a 0.8 transmission to-print distance until this becomes step Nr. 5. density. Therefore, the same 90% black, when printed (Again, refer to Chapter 8: Calibration for graphic with a No. 2 mixture, occurred at a greater negative presentation of the effects of printing time and density, showing an increase in printing speed. contrast mixture on a step tablet print.) In the No. 13 strip, the opposite is observed (see Figure 8.11). Now the 90% black is at a lower number We now know that a No. 7 medium mixture of with less transmission density. To produce the 90% 50% ferric oxalate mixtures A and B with a particular black under the same amount of light, it requires that the metal salt combination a shadow value of 0.65, exposed negative be less dense. The printing time is slowed. at 10 minutes, will give a 90% print black. In observing strips made from contrast mixtures We will now offend the purists by converting the No. 3 and No. 5, you will note printing speeds between 0.65 transmission density of the Nr. 5 step to a more the No. 2 and No. 7 strips. The No. 9 and No. 11 manageable 0.60.4 This will be your Speed Point. mixtures will show slower speeds to fall between No. 7 and No. 13. The eventual calculations will show FACTORINGIN THE EFFECTSOF CONTRASTCONTROL approximate linear speed changes from mixtures No. 2 through No. 13, to encompass slightly less than a one- Up to now, we have been dealing with negatives that stop increase or decrease in each direction from the will print with a platinudpalladium (Pt/Pd) No. 7, 50% No. 7 standard-a total range of almost two stops. mixture of ferric oxalate A and B. They therefore have the optimum density range (DR) of 1.4. For negatives deviating from that, we must alter the mixture of A and B, either adding or subtracting ANALYZINGTHE PRINTCURVE the restrainer found in the No. 7 mixture. This will change the printing speed, affecting the properties of To analyze and customize your own technique, you shadow values that are being used to determine printing must leave the computerized arena and investigate time. Less restrainer, as found in mixture No. 3, results manually drawn curves. Figure 13.1 represents the in less printing time than the No. 7 mixture. More standard graph used to plot paper densities. Note that restrainer, as with mixture No. 13, adds more printing the horizontal or x axis has been marked with increases in light at 0.3 log intervals, from left to right. The numbers are falling because they represent decreasing ,’. A Dmax of 1.50 is usually not attainable without special procedures, step tablet transmission densities. The vertical or y axis such as humidification. (See Chapter 10: Advanced Technique.) is scribed with paper reflection densities, also in 0.3 log However, for purposes of clarity, a hypothetical Dmnx of 1.5 is used intervals, increasing from the base to the top. throughout this book. With current papers and working at 50% humidity, a more realistic Dmnx may be 1.35 (1.35 x 0.9 = 1.21). Using reflection densitometer readings from the Realize that PtPd is not noted for its intense blacks. Its main attribute same strips that were produced during the contrast stud- is a broad, subtle scale with extended whites. Reaching great Dmnx is ies, each contrast mixture can be plotted (Figure 13.2). not that important for most imagery, a coizviizcing black will do. 4. These techniques are intended to save considerable time and expense in producing a good test print. They will not eliminate the fine-tuning Normally, we do not analyze the No. 1 contrast mixture strip and visual interpretation needed for the final print. Therefore, because there is no restrainer in the coating mixture. This, most likely, a deviation of 0.05 is hardly significant. will result in fog. 1 TO SENSITOMETRY FOR THE PLATINUM/PALLADIUM PROCESS

On the vertical y axis the reflection densities of each paper curve are plotted starting at just above 0, superiorly to a paper density of 1.50. At 1.35 (9oy0 of 1.50), a heavier 90% line passes horizontally and intersects each paper curve at its 90% black. It is here where paper exposure speeds are calculated. On the right are columns of numbers to serve as an aid in matching negative density ranges (DR) to mixture numbers, either expressed in ratios of A to B (Figure 13.2), or drops and concentrations of Na2 per twelve drops of coating (Figure 13.3). Also in Figure 13.3 are percent volumes of Na2. Note that except for mixture No. 2, only the odd numbers were used. Here, plotting reflective. densities, 2.4 2.1 1.8 1.5 1.2 0.9 0.6 0.3 0 Light Increase k a Family of Pt/Pd Curves has been produced similar to the computer-generated Figure 12.9. Note that all of the FIGURE 13.1 TkE CRApk UsEd TO Plor Liqh ANd DENSITY.As strips have a maximum black of 1.5. When a horizontal TkE liC,kT INCREASES fROM lEfT TO Ric,kT AIONq TkE X AXIS. PAPER line is drawn at the 90% black, or 1.35 reflective Rtf[ECTIVE dENSlTlE5 INCREASE ON rkt y AXIS. density, level the line intersects the film curves at different points.

A GUIDETO THE FAMILIESOF CURVES The paper curves represented in Figures 13.2, 13.3, and 13.12 were generated from reflection density THE NA~METHOD readings taken from Pt/Pd Ratio Method, Pd Na2, and Pd Ratio Method prints. Note that they are Those using chloroplatinate (Na2) as a contrast control identified by small numbers midway on the curve, agent with palladium can refer to Figure 13.3. The which are the contrast mixture numbers. In the case basic calibration test can be done with mixture 5s. The of Figure 13.3, The Family of Palladium Curves following portions of the text are presented for the Using Na2, space limitations prevent the suffixes Ratio Method using 50% platinum and 50% palladium. from being added to the mixture numbers. Conversions to the Na2 Pd and Ratio Pd Method can be The horizontal x axis, or base of the graph, shows done using the following chart, Table 13.1. (See also light increase from left to right. The boxed numbers Tables 7.1 and 7.2.) The dichromate method had been are the step tablet numbers exposed to the paper. added for completeness (see Table 7.6). They will not be considered in planning contrast or exposure times. The log numbers 3.0 to 0 decrease from left to right and show the transmission GRAPHICILLUSTRATIONS OF SPEED CHANGES densities of each step of the tablet. The higher log PRODUCEDBY CONTRASTMIXTURES numbers to the left show ultraviolet (W)light passed through the denser steps of the step tablet. In Figure 13.4, three curves are shown intersecting the On the right, more UV light has passed through the line for 90% black. The vertical lines projecting down- less dense portions of the step tablet. Note that the ward represent the speed changes produced by the paper curves rise in response to the light increase. different contrast mixtures. By noting where these The numbered vertical lines dropping a short way vertical lines cross the calibrated base of the graph, from the base mark the limits of each paper curve. we can calculate printing speed changes produced by the For example, the No. 7 line on the left indicates the contrast mixtures. The horizontal dotted line adjacent beginning of the No. 7 contrast mixture toe. The to the base represents the beginning of textured white. No. 7 line on the right indicates where the No. 7 contrast mixture crosses the 90% line. The limits of hy()I[ . For those not working with photographic each paper curve can be identified by these sets of sensitometry, the concept of speed changes tracking numbers. along the horizontal axis may initially be difficult + Reflection Density ? v! ? o! '9 '? r r r 0 0 0

0

-0 Y m4 m -cu g -r m m 0 t

-m

L -cu a,O D W h @i-r ...... 132 SENSITOMETRY FOR THE PLATINUM/PALLADIUM PROCESS

Reflection Density t 0 0 0

m--' rn X U 0 v) S

A- N- u- a- uld-m m- TABLE 1 3.1 EQLIIVA~ENICONIRASI MlYTL~RESfC)R Tkt RATIO PIIPd, Pd, NA2 Pd, AdDlCkROMAlt METhOd5 TkE Mld-CONTRAST ES VsEd fOR CA~I~RATION ARE PRlNTEd IN Bold TEXT

Negative DR Ratio Method PtlPd Na2 Method Ratio Method Pd Dichroinate Method Dropsl2OO

2.10 - - No. 1 Pt/Pd Pd 1.90 - - No. 2 1 1.85 - No. Is 2 1.so No. 1 - No. 3 1 1.75 - No. 2s 3 1.70 No. 2 - No. 5 1.60 No. 3 No. 3s No. 7 2 4 1.50 No. 5 No. 4s No. 9 4 8 1.40 No. 7 No. 5s No. 11 6 16 1.30 No. 9 No. 6s No. 13 8 32 1.20 No. 11 No. 7s 16 1.10 No. 13 No. 8s 32

Speed. (Due to more restrainer, the reduction of Printing Speed Faster metal salts is slower when exposed to a given amount of UV light.) The step tablet densities are also a constant.

0 When tracking the vertical lines from where each curve crosses the 90% line to the x axis, going from left to right, each 0.3 change represents a halving of II Printing Speed change or a doubling of exposure 5 II - 0.3 5 time. (Due to the increased restrainer, the reduction It B of metal salts is slower in response to a given _--- - Textured- Whte r -rl- 7 -I-- o amount of UV light.) 2.4 2.1 1.8 1.5 1.2 0.9 0.6 0.3 0 0 Greater printing speed means less printing time. 0 When going from right to left, each 0.3 change FIGURE 1 3.4 T~EINTI RSECTI(~N Of P~AiiNVMiPnllAdlul\1i/PA~~Adiu~lCLIRVI~ represents a doubling of Printing Speed change or AT YO% bhck a halving of exposure time. (Due to the decreased restrainer, the reduction of metal salts is faster in to grasp. Refer again to A Guide to the Families of response to a given amount of UV light.) Curves in this chapter. Remember that the numbers Lesser printing speed means more printing on the x axis represent light increase, from left to right. time. The log numbers (0.9,0.6,0.3, etc.) are the transmission densities of the step tablet. The lower the number, the In Figure 13.4, a portion of the No. 7 curve is shown more light is allowed to reach the paper. in the center. The solid center vertical line is projected The 90% black shown in Figures 13.2, 13.3, and from the point where that curve intersects the 90% 13.4 is a measurable and duplicable constant. In this black to the horizontal shadow density scale. The No. 7 case it is reflection density 1.35. mixture represents the standard from which other contrast mixture corrections will be made. (When If a more dense step tablet value caused the same using Na2, it will be mixture 5s.) 90% black, the contrast mixture has a faster Note in Figure 13.4 that, to the left, a portion of Printing Speed. (Due to less restrainer, the reduction another curve is shown crossing the 90% black. This of metal salts is faster when exposed to a given is drawn from a contrast mixture of a lower number amount of UV light.) containing less restrainer. The dotted vertical line If a less dense step tablet value caused the same 90% crosses the horizontal axis to the left of the solid line black, the contrast mixture has a slower Printing produced by the No. 7 mixture. In this case, a shorter 134 SENSITOMETRY FOR THE PLATINUM/PALLADIUM PROCESS

Highlight Density (IDmax) - Shadow Density (IDmin) = Density Range 1 Find Contrast Mixture

c No. 7 (5s) No. 7 (5s) > No. 7 (5s) (Nos. 1 through 6 -1 (Nos. 8 through 13 or 6s or 1s through 4s) through 8s) -1 -1 Corrected Speed Point Speed Point Corrected Speed Point > 0.6 = 10 Minutes 0.6 = 10 Minutes < 0.6 = 10 Minutes -1 -1 .1 Shadow Density Correction Shadow Density Correction Shadow Density Correction from 10 Minutes from 10 Minutes from 10 Minutes -1 -1 -1 Printing Time

printing time will be needed than with the No. 7 The Corrected Speed Point is shown as > (greater mixture. than) 0.6. This means that shadow densities To the right, a portion of a curve produced by higher than 0.6 will still print at 10 minutes. a contrast mixture containing more restrainer than the This is due to less restrainer. No. 7 mixture is represented. Here the projected dotted b. In Table 13.2,>(more than) No. 7 refers to line intersects the horizontal base to the right. A longer mixture Nos. 8 through 13 (Nu2 mixture Nos. 6 printing time will be needed. to 8). The Corrected Speed Point is shown asc(1ess than) 0.6. This means that shadow densities less than 0.6 will still print at 10 USINGTHE ALGORITHM minutes. This is due to more restrainer.

In learning the steps necessary-from the reading of the 3. Find the appropriate curve in Figure 13.2 (Ratio Pt/ negative to the calculation of printing time-it is helpful Pd) or Figure 13.3 (Na2 Pd). (Later in this chapter to follow a planned series of steps, or an algorithm, until I will present palladium with the Ratio Method. the process becomes more routine. A sample algorithm In that case the same calculations can be done using is presented in Table 13.2, and a series of steps follow Figure 13.12.) in the text. 4. For contrast mixture No. 7 (5s),project a vertical line from the 90% black to the horizontal axis. 1. Using the transmission densitometer, read the It should cross at 0.6, your Speed Point.' highlight and shadow values of the negative.6 5. For contrast mixtures Nos. lthrough 6 (Is through Do the subtraction to determine DR. 4s), see the left side of the algorithm. Note that 2. Determine the contrast mixture. Use your own data a Corrected Speed Point will be needed. Referring or refer to Tables 7.1 and 7.2 in Chapter 7: Choose to the Family of Curves for your particular metal Your Method. combination, find the curve for that contrast a. In Table 13.2, c (less than) No. 7 refers to mixture mixture and project a vertical line from the 90% Nos. 1 through 6 (Na2 mixture Nos. I to 4). black to the horizontal axis. It will cross somewhere between 0.8 and 0.6. That density is your Corrected Speed Point. (Look ahead to '. As 1 have emphasized textured values in the print, it is also necessary Figure 13.9.) to read the clear and dense portions of the negative where shadow and highlight textures are desired. If the negative has been well made, these are usually the clearest and most dense areas. If either the shadows or highlight areas of the negative are without texture (a frequent ''. If, for some reason, you choose not to calibrate at this point, use the occurrence with enlarged second- or third-generation negatives), the step tablet density that gave you a 90% black at 10 minutes printing print will reflect the same absence of values. time. 6. For contrast mixtures Nos. 8 through 13 (6s through 8s), see the right side of the algorithm. 4 t Note that a Corrected Speed Point will also be needed. Find the curve for that contrast mixture and project a vertical line from the 90% black to the horizontal axis. It will cross somewhere between 0.6 0.9 and 0.4. (Look ahead to Figure 13.11.) That density

is your Corrected Speed Point. 0.6 7. Using either your Speed Point or Corrected Speed P Point, do the shadow densities correction using the 0.3 2 9 actual shadow value of your negative. From this, - 9 working from the 10-minute printing time stan- 0; dard,* you will determine your printing time. This 2.4 2.1 1.8 1.5 1.2 0.9 0.6 0.3 0 Light Increase Exposure Scale -q will be discussed in detail later in this chapter and ___, 2.0.0.6 = 1.4 examples given. ?Speed Point

FIGURE 13.5 TkE NO 7 PlATlNUM/PAllAdlUM CURVE OR TkE NO. 5s Nn2 CURVE EXAMPLESOF VARIOUSNEGATIVE DENSITYVALU ES

While going through these exercises, refer the Table 13.2 In Figure 13.5, note the vertical line intersecting algorithm and the Family of Curves for your particular the base at 0.6. It is from a No. 7 curve. We know that metal combination (Figure 13.2, 13.3 or 13.12). After mixture was used for standardizing the light source; awhile, you will understand the process. Following that, therefore, it can be used as our standard. The 0.6 you will be able to make the first test strip surprisingly shadow density represents the Speed Point. close to what you have envisioned for the final image. After the IDmax and lDmin transmissions densities Only reprinting the test strip for fine-tuning will be are read and recorded, using you own data or referring necessary. For those who have worked empirically in to the Standard Negative Contrast Range charts in the past, you will be pleasantly surprised by the controls Chapter 7: Choose Your Method, you can determine possible for sophistication of imagery. your contrast mixture. Now you can calculate printing time. THE NORMALNEGATIVE THE SPEEDBAR Observe the No. 7 curve in Figure 13.5. If a vertical line is drawn down from its intersection of the When examining Figures 13.2, 13.3, and 13.12, note 90% black line to the x axis, it will fall at the 0.6 that the transmission density numbers at the x axis are transmission density. If, from that point, the logs are a logarithmic scale. That is, while moving a single point counted until the curve intersects the dotted horizontal to the left or right, densities are halved or doubled. line (textured paper white), the number is 2.0, a 1.4 However, the changes in printing time produced by the interval from 0.6. The exposure scale (ES) of the mixture density numbers are arithmetic, where the numbers are is 1.4. linearly spaced. For example, moving right from 0.6 to 0.3 would halve the printing time. Moving left from 0.6 to 0.9 would double the printing time. Some of us A Normal Negative with a 0.6 Shadow Density who are old enough will recall the slide rule. Scientists TRANSMiSSiON DENSiTiES: 2.0 - 0.6 = 1.4 and engineers used it for the same purposes as the present day calculator. The slide rule is simply two sliding bars imprinted with either a logarithmic or arithmetic scale. By sliding an arithmetic scale against a logarithmic scale, numbers in a logarithmic progression '. If you standardized at a printing time other than 10 minutes, you must calculate from that time. It is strongly suggested that the NuArc can be read in an arithmetic progression. be standardized at 400 units. The NuArc and other plate burners allow The Speed Bar is shown in Figure 13.6 and will be for such adjustments. used as a slide rule. Copy it to scale and place it at the 156 SENSITOMETRY FOR THE PLATINUM/PALLADIUM PROCESS

Speed bar for Printing Times Based on Ten Minutes

8o I i 40 I2Ol I’Ol l5 I 1 2.5 I I 1.25 I ---

70 50 35 25 16 12.5 8 6.3 4 3.1 2 1.5 1.Find the 90% shadow density vertical line for your contrast mixture. 2.Place the Speed Bar under the vertical line and position the arrow at that point. 3.Note the shadow value of your negative and look down to find your printing time.

~~~~~~~~~~~~ ~ ...~~~~~~~~~~.~~~~~~~~~~~ ~~~~ ~~~~~~~~~~~~ ~~~~~~~~~~~~~

4 I

8oo I I 400 I 1 2oo I I 1380 960 640 320 320 250 160 125 80 64

1.Find the 90% shadow density vertical line for your contrast mixture. 2.Place the Speed Bar under the vertical line and position the arrow at that point. 3.Note the shadow value of your negative and look down to find your printing time

FIGURE 13.6 Tkr SpEEd BAR Copv ikis &~dTkE sEltciEd FAMII~nf CURVESto the same scale CUTAT TkE dorrEd LINES Tkt uppt~ S(AIE IS fOR A SpEEd POINT bAstd ON 10 MlNLlTES TkE [OWER SCAlE IS fOR TkE NLIARCbA5Ed ON 400 ClNlTS base of Figure 13.2,13.3, or 13.12. Starting at the arrow 10 minutes, the Speed Point. Since there will be no at a standard 10 minutes (400NaArc units), printing further correction, the printing time is 10 minutes. times can be calculated for times less and more than the In practice, a shadow of 0.6 is too dense, and the standard. indicated printing time is equally too long. It has been In Figure 13.7, the top section of the illustration indicated that the “ideal” negative should have shadow shows a portion of Figure 13.2: Family of Platinunzl densities just above the base + fog (BfF). Referring Palladium Curves Using the Ratio Method. Note that in to Figure 12.4 in the last chapter, note that the IDmin Figure 13.7 the densities at the base of the graph match density is approximately 0.25, the desirable shadow the schematic below it. The intersection of the curve density.’ for contrast mixture No. 7 and the 90% black line is projected downward where it meets at a shadow density The “Ideal” Negative of 0.6. This is the Speed Point. In this instance it is 10 minutes. TRANSMiSSiON DENSiTiES: 1.7-0.3~1.4 The light source was distanced to provide that a No. 7 mixture (Nu2 mixture 5s) exposed for 10 An “ideal” negative will also use the No. 7 mixture minutes would produce a 90% black in step Nr. 5 of but will require a shadow density correction. Using the the step tablet (0.6 transmission density). Therefore, logarithmic calculations presented in Chapter 3: The a negative measuring 2.0 - 0.6 = 1.4, will duplicate Negative, we know that 0.3 is half the density of 0.6. this curve. Going back to the vertical line, one can deduce that this negative will require the same conditions that produced this graph: 10 minutes or 400 units of exposure. No correction for shadow values 9. For uniformity in this text, the log transmission density of 0.3 will be used to define an ideal negative shadow density. Some films, such as is needed. 400Tmax, will produce effective shadow densities lower than 0.3. Note that the Speed Bar has been placed in its Some, such as HI‘S+, will have values over 0.3. After mastery of this proper position. The arrow on the Speed Bar is at technique, changes can be made to accommodate different films. I I I I I I 3 I 60 90% - t t 4 1 55 t 5 1 50 I I I I 6 1 45 I I I I 7 1 40

I I I I 8 1 35

I 4 I I 9 1 30

I I I 1c 1.25 I I I I I1 1 20 x I I I 12 1.15 - - - 1 1 ! -13 -1.10 1 1 1 - - 1 1 I -

1 1 I I 14 is 12 ii in o 8 -I 32 -l-Stei N urn bers 1.8 1.5 1.2 .3 0 .9 I Exposure Increase- I 5 2 i 3 7 11 Graph Speed Point 1 2.4 2.1 1.8 1.5 1.2 0.9 0.6 0.3 0 I I I 4 I II I 1 I I I I I I I I

A I- 70 50 3525 16 12.5 8 63 4 3.1 2 1.5 I 1 .Find the 9040 shadow density vertical line for your contrast mixture. 2.Place the Speed Bar under the vertical line and position the arrow at that point. 3.Note the shadow value of your negative and 1004 down to find your printing time.

Referring again to Figure 13.7, follow the directions on This negative, while still requiring the No. 7 the Speed Bar: mixture, will need a shadow value correction that will increase printing time. If a shadow density of 0.9 is read 1. Find the 90% shadow density vertical line for your (0.3 +the 0.6 standard), the printing times are doubled. contrast mixture. Refer to Figure 13.7. This time, find the 0.9 density 2. Place the Speed Bar under that line and position the and look down. The printing time is now 20 minutes, arrow at that point. approaching the range of impracticality. 3. Note the shadow value of your negative and look down. WORKINGWITH INTERMEDIATESHADOW VALUES When shadow density variables of 0.1 exist, we can In this case, you would find your shadow adjust printing times in smaller increments. Instead of density to be 0.3. Look down for a printing time of halving or doubling the time, times falling in between 5 minutes. can be factored.

The Normal Negative with High Shadow Values A Normal Negative with a 0.4 Shadow Density

TRANSMiSSiON DENSiTiES: 2.3 -0.9= 1.4 TRANSMiSSiON DENSiTiES: 1.8 - 0.4 = 1.4 138 SENSITOMETRY FOR THE PLATINUM/PALLADIUM PROCESS

This negative still requires the No. 7 mixture. It is the exposure scale (ES) for this mixture. For example, close to ideal, so it will need only a minor shadow the No. 2 curve intersects the 90% line at a 0.8 value correction. Here, a shadow density of 0.4 would transmission density. At its intersection IDmin at 2.5, fall 1/3 between 5 minutes (0.3) and 10 minutes (0.6). subtract 0.8 for an ES of 1.7. In Figure 13.7, find the 0.4 shadow density and look down. It is 6.3 minutes.'" \OII To avoid any confusion, realize that in the following sections, I will refer to medium-, high-, and low-contrast negatives. The paper contrasts to accom- A Normal Negative with a 0.8 Shadow Density modate these negatives will, of course, be medium, low, TRANsMissiON DENsiTiEs: 2.2 - 0.8 = 1.4 and high, in that order. This is the first practical example of how lower- In this negative, the shadow value will require a contrast mixtures increase printing speed. In corn- considerable increase in printing time. Following the parison, a No. 7 PtPd contrast mixture with the Speed Bar, find your shadow value of 0.8 for a printing same 0.8 shadow density would yield an approximate time of 16 minutes. 18-minute printing time. As you will see later, a low- contrast negative with a 0.8 shadow value calling for THE HIGHXONTRASTNEGATIVE a No. 13 mixture would require a 35-minute printing time! Figure 13.8 represents a curve drawn from a No. 2 Pt/Pd mixture (Na2 mixture 2s). The point at which the curve intersects the 90% line is IDmax. When a vertical line A High-Contrast Negative with a 0.8 Shadow Density is projected from that point to the base of the graph, TRANSMiSSiON DENsiTiEs: 2.5 - 0.8= 1.7 it intersects the line at 0.8, the shadow density used to construct this curve. This is the Corrected Speed Point for a No. 2 Contrast Mixture. It is from here that Note in Figure 13.9 that the shadow density of the shadow value corrections must be made. Working at the negative is 0.8. The Speed Bar has been moved to where base, or x axis, measure the span from the Corrected the arrow lines up with 0.8. This negative duplicates Speed Point to where the curve actually intercepts the the print made using the step tablet at the No. 2 mixture horizontal line at textured white (IDmin). This is at 2 0 minutes. Therefore, the printing time is the same: 10 minutes.

A High-Contrast Negative with a 0.5 Shadow Density TRAN5MkiON DENSiTiES: 2.2 -0.5 = 1.7

1.2

0.9 I I I I I I I IIIII 0.6 I I I I I I I IIIII 14 13 12 11 10 9 8 7 6 5 4 3 2 1cStepNumberS

1.8 15 12 9 0 0.3 3 Exposure Increase 4

-4 -4 Exposure Scale 25-08=17 !Corrected Speed Point

lo. Some with a background in mathematics will observe that we are dealing with segments of a logarithmic scale, so the calculation of intervals is not entirely correct. The method presented is, however, close enough to produce very good test prints. Refer to Figure 13.9. The Speed Bar has been positioned at the Corrected Speed Point for this curve. A Low-Contrast Negative with a 0.4 Shadow Density Find the shadow density of the negative described. It is TRANSMiSSiON DENS~T~ES: 1.5 -0.4~1.1 0.5. Find 0.5 at the base of the Family of Curves graph. Look down. The printing time is 5 minutes. Now the Speed Bar has been moved to the right so A High-Contrast Negative with a 0.3 Shadow Density that the arrow lines up with the Corrected Speed point of 0.4. The printing time is 10 minutes (Figure 13.11). TRANsMis5iON DENsiTiEs: 2.0-0.3=1.7 A Low-Contrast Negative with a 0.6 Shadow Density Again refer to Figure 13.9. The Speed Bar has been positioned at the Corrected Speed Point for this curve. TRAN5Mi55iON DEN5iTiE5: 1.7 -0.6 = 1.1 Find the shadow density of the negative described. It is 0.3. Find 0.3 at the base of the Family of Curves graph. As often is the case with less contrasty negatives, Look down. The printing time is 3.1 minutes. if times must be adjusted for shadow density, they will be longer than 10 minutes (see Figure 13.11). With the By now, it is apparent that once the Speed Bar has been positioned at the Speed Point of a particular curve, Speed Bar in place, find the 0.6 point on the graph. Look down. The printing time is 16 minutes. it does not need to be moved again. All shadow densities can be calculated from there. A Low-Contrast Negative with a 0.9 Shadow Density THE LOW~ONTRASTNEGATIVE TRAN5MiSSiON DENSiTiES: 2.0-0.9= 1.1 To analyze the other extreme, note the No. 13 curve (Nu2 mixture 8s), found in Figures 13.2 or 13.3. It will intersect the horizontal 90% line to the right of the It is in this area that things can rapidly get out No. 7 curve. Drop a vertical line from where it intersects of control. With a No. 13 mixture, a shadow density of the 90% line to the x axis. It should fall at the 0.4 0.9 requires a correction of almost two stops. Find 0.9 transmission density, indicating that it is 2/3 stops and look down. The printing time is 35 minutes! slower than the No. 7 mixture (0.6). This means that an appropriate negative with a shadow density of 0.4 At some point, reciprocity failure will come to will produce a 90% black at a printing time of 10 haunt you-another good reason for controlling minutes. This is the Corrected Speed Point for the No. shadow densities. 13 (Nu2 8s) contrast mixture. Also, note that at the When adjusting for contrast, recognize the follow- base, the exposure scale is 1.1 (Figure 13.10). ing factors.

INTERMEDIATECONTRAST MIXTURES Using the above principles and referring to the Starzdard Negative Contrast Ranges in Chapter 7:Choosing Your I/ - 1.5 90%Black

I I I I I I I IIIII 14 13 12 11 10 9 8 7 6 5 4 3 2 1cStepNumbers

--__ I I I tI I I 2.4 2.1 1.8 1.5 1.2 0.9 0.6 0.3 0 80 40 20 110 5 2 5 125 --- Exposurescale 4 A 15-0.4= 1 1 Corrected Speed Point FIGURE 15.1 1 Tlir RATIC)No I 3 PTIP~OR NA~MIXILIRE 85 FIGURE 15.10 TkF No I3 OR NA~MixIIiRt 85 C~ii<\t ClRVt fOR A LOU-CONTRA51 NEC,AII\E UlTk IhF 3PFFd BARIh P14CF 140 SENSITOMETRY FOR THE PLATINUM/PALLADIUM PROCESS

Reflection Density b ? 2 2 2 0 W x : N m m

n D _.7 7 N b m-

0 PLATE 13.2 TASMAN SF4, NFWZEAlANd. 1999 7 X 17 iNck Pd This PRiNT WAS MAdE bv fOLlOWlNC, T~EPRiNCIplES PRESENTEd IN rkis CkApTER. wkllr iT CONTAINS A full RANCE Of TONES, IT dOFs hOT (ONVEV TkE iMpRESSlOY I had WhEN COMpOSiWC, iT. IT IS A "C\iNICA[" OR TEST PRINT, NEEdiNG REVISIONS UNTIL iT is \,lSUA[[Y SATiSfVlNC,.

PLATE 13.3 TA~MANSEA, NEWZEA~A~~ 1999 7 X 17 INCh Pd Tk15 VERSION Of TkE PRINT hAS bEEN ModlflEd TkE USE Of \ARIOUS TEST STRIPS Tkls WAS WkAT I INTENdEd UkEN IT WAS "pRELISUA[12Ed" AS A pAllAdltlM PRINT

Method, as well as Figures 13.2, 13.3, and 13.12, the in technique, the properties of materials are quite printing times can be calculated for all contrast mix- consistent. If, for example, your tests match the curves tures. For the even-numbered mixtures that are in this text, the Speed Point and Corrected Speed Points not shown in these Families of Curves, simply position for each contrast mixture will remain a constant. You a point between the two nearest curves. Drop a vertical can interpolate this published material with your own line from where each contrast mixture crosses the 90% work. If, in the future, the controls go astray, you know black line. The point at which the vertical line intersects that some quality control is in order. In most cases it will the horizontal axis establishes the Corrected Speed Point be that the light source intensity is drifting or that a for that mixture. It is from there that corrections are particular paper has changed. Metal salts and fresh made for shadow density. sensitizers purchased from a reputable supply house are quite stable and are rarely responsible for any deviation of controls. Note that some paper developers differ BEINGPRACTICAL considerably from the potassium oxalate that was used to establish this data. THE SPEEDPOINT AND THE CORRECTEDSPEED POINT PAPERS We have engaged in some minutia to convey the principles of printing time calculations. If you have The material presented here will be applicable, with indeed stabilized your light source to print a Nr. 5 step in minor adjustments, for most papers. If, however, you the 90% black, it may not be necessary to construct your choose to use one of the thicker art papers, or if you own graphs. We have found that regardless of differences double coat, you may need to recalibrate your light 142 SENSITOMETRY FOR THE PLATINUM/PALLADIUM PROCESS source for that particular paper. See Chapter 5: Paper, USINGPORTIONS OF THE PAPERCURVE for additional information. USINGINTERMEDIATE TONAL VALUES THE INTERPRETIVEPROCESS Up to now, I have utilized the paper curves to calculate a full tonal range print, a print that exhibits a total While working to understand densities, curves, scales, scale of all possible tonal values. One of the advantages and the computations necessary to make a print contain- of working from curves, however, is that a print need ing a full range of tones, we must also remember that we not be placed to encompass both the absolute shadow are dealing with a visual art form. The final print should and/or highlight values. not be the product of “number crunching” but of using A perfect example of deviating from this practice the right side of the brain to produce an image that has is the creation of a high-key print: one that contains met our visual Rarely does a first print derived goals. textured highlights, but stops short of exhibiting the from sensitometric readings qualify. Referring to Plates darker registers. As one might conclude, if only a 13.2 and 13.3, the first is what I term a clinical print. In portion of the curve is used, the negative need not have the days when monochrome was used for illustrative the DR called for at a particular contrast mixture. purposes, such as medical photography, it would have Or, a contrast mixture may be chosen that exceeds the served that purpose. For us, it should be the first of a DR of the negative, allowing the use of only a portion of series test prints until it has been “tweaked” visually of the curve.” to our satisfaction, as in Plate 13.3. By initially under- The steps in utilizing a portion of the curve are standing the means to make a full tonal value print, and a bit more complicated in that two steps are involved: then learning to effectively modify it using visual the calculation of printing time for a full tonal value feedback, we can save the labor and materials usually print and, then, recalculation for the printing time of a expended by those who print by trial and error. less than full tonal value print. For printing at a portion of the curve, the following steps are needed: PALLADIu M Compute the DR of the negative. Choose the contrast control method and metal. In the last chapter, we discussed the extended toes and (I recommend Ratio Pd.) tonal ranges of pure palladium. Also, I recommended Using the previous exercises, calculate printing time. that the use of palladium with the Ratio Method be By means of a marked piece of paper representing limited to the higher density ranges where the chlorate is the DR of the negative, slide it laterally under the not needed in sufficient amounts to cause paper floccula- base of the Family of Curves to find a new curve of tion. The speed changes related to contrast mixture are greater DR. quite similar to those observed with Pt/Pd, but because of Continue to slide the paper until a portion of that the greater DR of palladium mixtures, the speed changes curve is chosen. may be more pronounced, particularly with the low- Recalculate a new printing time. (This usually will contrast mixtures. It is important that, regardless of the be less than the original time.) material used, you verify your own Speed Point. Figure 13.13 represents a curve for a Ratio Pd In Figure 13.12, note that, except for the greater No. 2 mixture. A negative with a 1.4 DR would ES and more of a horizontal spread in the curves, the normally call for a No. 11 Pd Ratio Method contrast Palladium Family of Curves is quite similar to the other mixture. By positioning it toward the high end of Families of Curves. The Speed Point and Corrected the curve (to the left, therefore, decreasing exposure), Speed Points for various contrast mixtures are the same. we have kept the highlights near paper white. Note, The same principles apply when calculating printing however, that the blacks now fall in the low midrange times. ’ ’ of the paper scale at a reflected density of 0.8 (Zone IV). 11. Some printers have reported palladium to have a slower printing time than Pt/Pd. This observation is based on the use of an identical negative. Due to its greater ES, palladium requires a negative of more 12. One of the joys of teaching workshops is to find a negative from contrast than Pfld. If negatives of the same DR were to he used for a talented student that has been made for silver and, therefore, has a both PdPd and palladium alone, for an ES to match the DR of the short DR. When such a negative (LISLI~II~a portrait or nude), is placed negative, palladium would require more sertsitizet than WPd, thus in the upper registers of a palladium curve. the result, many times, is slowing the printing speed. exquisite. calls for more contrast in the negative. You may find that your paper markings will incorporate only the toe and mid portions of the curve. You can visualize your print by imagining the “Zones” that might be 0.9 displayed. While doing these exercises, it is helpful to refer to Figure 12.15, the MatcherR File for 0.6 palladium in the last chapter. Also note that Plate 12.2: Salmon River has been printed emphasizing 0.3; high values to accentuate the sun and its halo. 3- 3 The dock, while appearing black, falls in the OI I I Zone IV to V areas. 2.1 1.8 1.5 I 1.2 0.9 0.6 0.3 0 A 14DR Negative d I 5. If you are satisfied, note the new contrast mixture -Exposure Scale 2 7.0 8 = 1 9 Y and compare, as before, your shadow value with I New Speed Paint i-fnrrected Speed Point the density indicated on the graph. 6. Look at Figure 13.13. Here, the negative has a 80 40 20 10 5 2.5 1.25 --- DR of 1.4. To print as a full tonal value print, it would need palladium Ratio Mixture No. 11. However, palladium mixture No. 2 was chosen. Slide the paper to the left until the negative reaches the end of the toe at 2.7. Now the other end, which should produce paper black, is now at 1.3 To USEA PORTIONOF THE CURVE on the horizontal scale. This is the New Speed Point. If projected upward to intersect the curve, and 1. Read the negative on the transmission densitometer. then right to the y axis, it intersects at about 0.95. Record the highlight and shadow densities. Perform If the 90% black line was in Zone 111, it is now in the subtraction to determine the DR. Note the Zone IV (see Figure 12.15). Therefore, a print will be numbers in the right columns in Figure 13.12. made with a textured long toe with shadows only in For example, a negative of 1.4 DR would call for the Zone IV area, just like Plate 12.2: Salmon River. a No. 11 Pd mixture. 7. Calculating printing speed is the reverse of the 2. Place a scrap of paper at the base of Figure 13.12. previous exercises. Keep in mind that as you are Find the No. 11 vertical lines extending below the going to the “high key” part of the curve, the base. These lines are extensions from where that printing time should be less than needed for a print No. 11 curve meets IDmin on the left and a vertical showing Zone I11 shadows. This time, use the Speed line dropped from IDnzax where the curve crosses Bar as an aid to negotiate the printing time changes the 90% line. Mark the scrap of paper with the along the logarithmic scale at the base of the graph.’j density values at the No. 11 vertical lines. For example, a negative with a 1.4 DR would be 1.85 for a. Find the New Speed Point. Line up the Speed highlights and 0.45 for shadows. (0.45 is half way Bar so the previously calculated printing time between 0.6 and 0.3.) The left portion should match for a full tonal ualue print is at that point. where the curve intercepted the line for textured b. Referring again to a 1.85 - 0.45 = 1.40 nega- paper white (IDnzin).The right side of the paper tive, note that printing time was 10 minutes. will lie at the point where a vertical drawn from c. Knowing that the printing time will be less than the curve interception with 90% black would fall. the 10 minutes shown by the arrow, we travel 3. Using the Speed Bar as before, calculate the printing to a Corrected speed Point of the No. 2 curve. time for a full tonal value print. For a negative Look down. the printing time is 3.1 minutes. (See Figure 13.13) 1.85 - 0.45 = 1.40, the printing time would be d. For the second example, 1.70 - 0.30 = 1.40. 10 minutes. For a negative 1.70 - 0.30 = 1.40, The printing time for a full tonal value print was the printing time would be about 6.3 minutes 6.5 minutes. Line up 6.5 with the New Speed (actually, 6.5). 4. Now, sliding to the left and right, see how the paper As the Speed Bar allows for arithmetic calculations from a markings fit in the other curves. If you are planning logarithmic scale, it also can be used to track printing time changes a high-key print, find a curve to the left, one that from one shadow density on the Family of Curves to another. 144 SENSITOMETRY FOR THE PLATINUM/PALLADIUM PROCESS

Point. Look to the Corrected Speed Point and of a nude or portrait. We can choose a curve at random. down. The new printing time is 2.5 minutes. By sliding the marked piece of paper laterally, we can pinpoint the portion of that curve where we want the From the calculations shown, printing times have flesh tones to appear (usually on the left side of the ranged from 10 to 2.5 minutes, a factor of four. If mid portion, Zone VI). If that is not satisfactory, we can working from trial and error, how many prints would choose another curve. be necessary before an accurate printing time was Conversely, the same procedures can be used to discovered? plan a darker, more somber image using the darker This technique takes a little practice, but it is quite tones and eliminating the higher values. In this case, the valuable for prints that are to be less than full tonal pencil markings would be shifted to the right portions range. This is most useful when calculating the printing of the curve, calling for mow printing time. 145 146 APPENDIXA

THE 0x1DATION REDUCT ION REACTION Appendix F: Ultraviolet Light Sources for Palladium and Platinum Printing.) Since the process is directly related As with many types of photographic printmaking, to the amount of exposure to UV light, the photographic including the silver gelatin process, the platinum/ negative serves as a vehicle to selectively filter the light palladium image is dependent upon the reduction of to create an image. After exposure to UV light, the electrically charged metal salts to the uncharged metallic converted iron salts can be observed as a yellowish state. In this oxidation-reduction or redox reaction, printing-out image. The following demonstrates the there is a change in the oxidation number of one or reduction of ferric oxalate to the ferrous form. This is more elements. The oxidation number, or oxidation a portion of a complete equation and is, therefore, not state, is determined by the transfer of negatively charged balanced. electrons. UV light Oxidatioiz is the loss of electrons, or an increase in or the oxidation number. Fez (clod3 Fe (CZ04) Reduction is the gain of electrons, or a decrease in Ferric oxalate (Fe’+) time Ferrous oxalate (Fe”) the oxidation number. Note that, as time is also a factor in facilitating reduction, outdated mixtures of ferric oxalate will contain excessive amounts of the ferrous salt. If used, the ferrous oxalate will cause a diffuse amount of the THE REDUCTIONOF METALSIN PHOTOGRAPHICmetal salt to be precipitated as fog. For this reason, PRINTMAKING it is best to use only fresh ferric oxalate.

Chemical equations must be electrically balanced. If In a second reaction, this reduced form of iron one or more elements are reduced, other elements must (ferrous) is then oxidized to ferric oxalate, which serves be equally oxidized. In the case of the reduction of silver, as a reducing agent for the platinum or palladium salts. the silver salt Ag+ is reduced by the addition of one In the process of reverting to the ferric state, it gives negatively charged electron to metallic Ag . In the off an electron. In this phase, the Pt or Pd salt loses its process, the developer is oxidized. positive valence state and is reduced from Pt+’ or I’d+’ The platinudpalladium process is only a bit more to Pto or Pd”, the elemental state, which precipitates on complicated. The metallic salts contain more than two and into the paper. elements, but the principle is the same. In the case of This can be expressed with Berkeley’s Formula. platinum, three elements comprise the salt: potassium (K+), platinum (Pt2+), and chloride (Cl-). The com- pound is called potassium chloroplatinite and is depicted BERKELEY’SFORMULA as K1PtC14. The palladium salt contains sodium (Na+) in place 6 Fe(CLO4)+ 3 K~Ptc1412 FeL(CZ04),3 + 2 (FeCI3) of the potassium and is termed sodium tetrachloro- Ferrous Potassium Ferric Ferric palladate, or NalPdC14. oxalate chloro- oxalate chloride The platinum or palladium process uses another platinite salt, or sensitizer, as part of the coating to facilitate + 6 KCI + 3 Pt’ the reduction process. Iron is one of many compounds Potas- Elemental to exist in more than one positive oxidation state: sium platinum chloride Ferric Fe3+ Ferrous Fez+ With palladium, the equation can be expressed as such: The seizsitizer salt, ferric oxalate, or Fez (C204)3 6 Fe(C2O4)+ 3 NalPdCl4 +2Fe2(CZ04)3 + 2(FeC13) Ferrous Sodium Ferric Ferric contains iron (Fe) in a state that easily accepts an oxalate tetrachloro- oxalate chloride electron to change to the ferrous state, or ferrous palladate oxalate, Fe (Cl0,). This reduction occurs with time, + 6 NaCl + 3 Pd- or is rapidly expedited by ultraviolet (UV) light in Potas- Elemental the 200 to 400 nanometer range. (See The Ultraviolet sium palladium Light Source in Chapter 2: Setting Up a Laboratory and chloride A developer facilitates the process, causing the (restrainer) can be introduced to allow for contrast platinum (and palladium) in the coating to convert to control, either as part of the sensitizing ingredients pure metal. Much of this process is one of electron used in coating the paper or in the developer. The ferric- transfer that requires moisture for conductivity. This ferrous equation can be used to demonstrate the effect is further affected by humidity, pH, temperature, and of a small amount of hydrogen peroxide to re-oxidize developer composition. The relative insolubility of a portion of the ferrous oxalate. ferrous oxalate, while in the developer, attaches to the metal salt until the process of reduction is complete. The sensitizer not exposed to UV light remains in the REDUCTION ferric state, which is highly soluble and amenable to UV light clearing procedures (Schaefer, 1998). (Reduction) Platinum and palladium are referred to as "noble" Fez (CZO~)~- Fe (C204) metals: As metallic elements, they are highly resistant Ferric oxalate (Fe")-Ferrous oxalate (Fez+) to combining with any other chemical element or H202 compound. The archival permanence of the platinum (Oxidation) and palladium print is due to this phenomenon.

PALLADIUMPRINTING WITH SODIUM OXIDIZERS c H LOROP LATI NAT E ' * Oxidizing agents electrons, thereby oxidizing gain As discussed, the palladium salt in sodium chloropall- elements by acquiring their electrons. One of the most adite (Na2PdCI4) commonly used in palladium print common is hydrogen peroxide which is capable (HLOl), making, is in the +2 Oxidation State (Pd+'). As with to to of accepting an electron be reduced H20. To platinum, it is reduced to the elemental state (Pd') by the balance this process, the extra oxygen atoms (0)are reoxidation of ferrous oxalate. In oversimplified terms, converted to naturally occurring oxygen gas (02). one can assume that since a single electron is transferred Compounds of chlorate, dichromate, and sodium in the reaction, two equivalents of ferrous are needed chloroplatinate have the same effect of strongly attract- for each of the two electrons transferred in the reduction ing electrons. of palladium salt to the element. 2 Ferrous oxalate (Fet2) 1-2 Ferric oxalate (Fe+3) OXIDATION Pd+' + Pd"

2H202 +2H20 + 02 The platinum in sodium chloroplatinate (NalPtCI,) is in the +4 oxidation state (Pt t4)[+4]. When combined When an oxidizer is introduced into photographic with ferrous oxide, two more units of ferrous are chemicals, the effect will be to arrest the process of consumed. Howard Efner has described the double reduction from a metallic salt to its elemental form. reaction as follows. In photographic paper, two reactions are observable. The printing speed of the photographic paper is slowed *[PtC16]-' + 2 Fe+' -[PtC14]p2 proportional to the amount of oxidizer added. Also, *[PtC14]-' + 2 Fe+' -Pdo + 4 Fef3 since the blocking of the reduction of the metallic salt is related to the concentration reacted upon, the slowing of As each equivalent of Na2PtC16 consumes four of the reaction is not linear, but causes a disproportionate the ferrous salt, the salt is not available for the reduction slowing of reduction in the shadow and highlight areas. of the palladium salt to the metal state. The result is (The highlights, containing fewer salts, are more a retardation of the reaction similar to that effected profoundly affected). The net effect is that of shortening by other oxidizers. As with the more commonly used the latitude, or the exposure scale (ES) of the paper. When an oxidizer is used photographically, it is referred to as a restrainer. '. This is hased on Howard F. Efner's discussion from Contrast Control Contrast control for the platinum or palladium for Iron Based Prrriting (2001).It is presented with his kind permission. print can be achieved in a number of ways. An oxidizer '. More accurately, the compound is sodium hesuchloroplatinum (IV). 148 APPENDIXA

oxidizers, the slowing is not linear, causing a decrease more at the highlights than the shadow areas of an in the exposure scale of the print. image. This decreases the exposure scale of the paper, increasing its contrast.

USING NA2 IN THE TRADITIONAL PLATINu M/ PALLADIu M PRI NT CLEARING I did one test using a 50% mixture each of potassium chloroplatinite and sodium tetrachloropalladite com- While the platinum and palladium metals are bined with an equal measure of ferric oxalate. To permanent, the salts remaining after reduction are this was added 20% Na2 (sodium chloroplatinate) in not. They will continue to react with one another various proportions. Regardless of the concentration and with impurities in the environment. They must, of Na2 used, every restraining effect was noted with therefore, be removed. The clearing agents used in a constant ES of 1.5 for each mixture. the platinum/palladium process are either dilute Another test was done varying the proportions of acids or ethylene diamine tetraacetic acid (EDTA)/ potassium chloroplatinite and sodium tetrachloropal- sulfite compounds. Both facilitate the removal of the ladite in 4:0, 3:1, 2:2, 1:3, and 0:4 ratios. Little metal and iron salts from the paper. When in difference of image color was observed between the solution, these salts can be eliminated by successive various Pt/Pd mixtures. clearing baths and washing. Inadequate removal of Howard Efner has explained these observations the salts results in stain. by suggesting that the platinum I1 salt (KlPtC14) will Under most conditions, the clearing bath must exchange with the platinum IV salt (NalPtC1,) yielding remain acidic to keep the iron salts in the soluble insoluble KZPtCI,. This effectively takes the Pt IV salt oxalate state. If the clearing agent (or developer) is (Na2)out of the solution, making it relatively unreactive. allowed to become alkaline, insoluble iron hydroxide may form, which resists further attempts at removal. The traditional dilute acid baths and hypo clearing IN SUMMARY agents (because of the presence of acidifying sodium metabisulfite) accomplish this purpose. Sodium chloroplatinate (Na2PtC16),when used with the Nevertheless, an alkaline clearing bath may be palladium salt (Na2PtC14),has the effect of consuming used if EDTA is employed. EDTA is a powerful the ferrous oxalate, which normally would reduce the chelating agent that dissolves the iron salts from the palladium salt to metallic palladium. The net result paper without the necessity of an acidic solution. It is is a dispropovtional slowing of the process of reduction, commonly used with sodium sulfite. 149 1 50 9 APPENDlX B

The report of my death was an exaggeratioon. and revise the score. Would this combination ever go -Mmk TwAiN. I897 beyond initial rehearsals? Obviously, never! The net outcome may be perfect, but sterile.’ Using available digital technology, it is easy to THE IN~AMERANEGATIVE program the performance to perfection (the Epson printer). However, regardless of the Photoshop ’ wiz- Since the publication of the first edition of this ardry employed, there remains the intangible perception text, advances in computer technology have accelerated of a contrived image. to the point where only the most dedicated professional can stay at the cutting edge. The making of computer- generated negatives has now become the norm for DARKROOMMAGIC enlargement of negatives, mostly displacing the art of In defense of the computer image, it has been said the photomechanical reproduction. Now, there is little most traditional photographers have used “darkroom discernible technical difference between a negative magic” to manipulate their images to no lesser extent made in-camera and one generated from a computer. I than that available via computer technology. This, have no doubt that in the near future, the gap will close however, occurs during and after the visual inter- to where the two become indistinguishable. pretation of the image-after the final product has With a little knowledge of Photoshop”’ and a decent been viewed on numerous occasions over time, under ink-jet printer, the photographer can manipulate the different lighting, and with various audiences. image to his or her satisfaction and then print perfect Prominent musical performers, either conductors negatives, each with identical contrasts and densities and or soloists, follow the same process. All have continually matched to a single contrast mixture and printing time. honed their interpretation, based on years of study, In fact, decent enlarged negatives can be made from reflection, and feedback, until they are capable of a 35mm color transparencies. unique personal expression of the score set before them. With this preamble, the reader may ask why I have devoted a significant portion of this text to the in-camera negative? THE CLINICALPRIN~ Those who have mastered negative control often can return from a project with a complete series of PERFECT,BUT STERILE technically perfect in-camera negatives. It would be The computer is only one more tool to be used in the quite possible to train a laboratory assistant to mix photographic process. As such, it should be approached a standard palladium coating and use a predetermined as an adjunct to, and not a replacement for, traditional printing time to make a print from each negative that photographic technique, particularly as applied to an covers a full of range of tonalities and would meet the historic alternative process. In particular, those platinum/ criteria of what I have termed a clinical print. (See palladium photographers who rely solely on the com- Chapter 13: Using the Print Curves.) puter, without learning the nuances of previsualization and printing, are at risk of producing uninspired, “cookie cutter” prints from “cookie cutter” negatives. THE INTERPRETIVEPROCESS In photographic terms, Ansel Adams compared the A clinical print, however, should only represent the negative to the score, and the print to the performance. starting point for a series of interpretations using the Today’s computer technology, with musical software, techniques described in this text, until satisfaction is has made the composing of a score a series of achieved. Moreover, if one were to study the work of computerized notations on the monitor, bypassing the legendary photographers, it will be noted that, over laborious task of penciling in the key, clef, signature, the years, the printing of individual images has under- notes, meter, dynamics, and other guides to perfor- gone a series of refinements so that early prints may mance. To carry the analogy further, it would be a be notably different from those made later on. rather simple task to create a computer model that could program a piano or an automaton “conductor” to carry out the performance of the score to perfection. ’. In fact. at this time, the composing and scoring of some movie and pop music is entirely computer-generated, even to the point of If, upon performance, the desired effect was not eliminating live musicians. Here, there is no better example of a sterile achieved, the composer could go back to the computer and contrived product. Thus far, a position can be taken that, in the hands images will almost invariably reflect the attributes of of an experienced printer, it does not matter whether speed and efficiency inherent in roll film (or digital) a good negative is made in-camera or with a computer, camera. as long as he or she has the skills to modify the printing process to attain satisfaction. That is true. . . up to a “IN THIS BESTOF ALL POSSIBLEWORLDS” point. -VOLTAIRE, 1759 Can the computer-oriented photographer produce work THE CONTEMPLATIVEIMAGE of a contemplative nature? Most certainly! In Appendix The chapter-heading image (Plate B.l Tennis Courts, E: Crafting Digital Negatives for Contact Printing Gregynog, Wales. 1993) was made during a four-week Platinum and Palladium, Mark Nelson describes a visit to the British Isles. Before this exposure, I had spent technique where, through constant visual feedback 10 days without setting up the 7 x 17 inch camera. from the monitor, to the ink jet negative, to the study During the entire visit, I had exposed negatives for print, and back again, a careful worker has the options approximately 12 images (two sheets of film each). to integrate the computerized image into the whole Of those, only this image and one more made the palladium printing process. Then, Nelson introduces the “final cut.” technique to modify the palladium printing options, For my longest trips overseas, I have never packed such as contrast and printing time, to achieve the final over 60 sheets of film (again, two sheets per image). print. This is not a “cookie cutter” approach to photo- Does that mean that I lack inspiration? Possibly. graphy. In fact, having these controls may very well discourage the temptation to plunge into the limitless basket of Photoshop’ goodies. If the photographer THE VIEWCAMERA TRADITION starts with a scan of a well-previsualized view camera The platinum/palladium process originated and flour- negative, it may be the “Best of All Possible Worlds”’ ished during the late nineteenth and early twentieth Regardless of the format used, in this frantic and centuries. The images were, without exception, done frenetic beginning of the twenty-first century, it might with a view camera. Although I do not suppose to put be wise to appreciate a time when photographs were myself in their place, the notable platinum photogra- made for serious reflection (perhaps over a glass of phers of the time, from P.H. Emerson and Frederick Scotch while listening to J.S. Bach). Despite attempts Evans to Paul Strand, produced images of a contempla- by some photographers to capitalize on the title tive nature. Many times, the number of film holders they PLATINUM, the process does not lend itself well to owned or could carry limited the exposures they could images designed for the 30-second attention span. do in one session. This has not changed with time. View camera A NEEDFOR SUBTLETY workers have learned that when the camera is set up, care needs to be taken before each exposure, lest they Time magazine ran an obituary for the great British run out of film and miss a better opportunity just actor Sir Alec Guinness that said: “In an era when around the corner. This selectivity is reinforced by the grossness is king, subtlety needs to be honored.” laborious task of setting up and focusing the camera. Perhaps this may also define the attributes of a good Even if the setting is in the studio, where film may be photograph-one that takes a bit of sensitivity and available in abundance, the film holders still must be effort on the part of the viewer to be understood and is, inserted, the lens prepared, and the dark slide removed, giving time for thought and contemplation. One learns by necessity to refine one’s vision. Film is not wasted on ’. Having recently learned Mark’s method of digital negative enlargement, I am more firmly convinced that it, or any other digital careless or thoughtless endeavors. program, is optimized when starting from well-seen and perfectly Does that mean that small- or medium-format exposed and processed negative. When the negative is scanned at photographers cannot, following photomechanical or 16 bits, it can be prepared at that level in Photoshop CS’ with minimal computerized enlargement of their negatives, produce loss of information. Relying on Photoshop” to repair a casually made images equally suited to the Pt/Pd process? Perhaps, negative will seriously deteriorate the image file, as well as add a measure of artificiality that can be perceived in the final PtPd print. but their photographs may not be the same as those Moreover, to produce a finished Pt/Pd print of any substance from composed carefully on the ground glass of a view a digitized negative, one must have mastered the techniques inherent camera (upside down, no less). Unless care is taken, their in the medium. 152 APPENDIX B

for the most part, antithetical to much of the current art scene. The Report of the Death of the View Camera is an Exaggeration.

Given that platinudpalladium is, by necessity, a contact printing process, three choices of negative construction are available:

The original negative exposed directly in the camera Photomechanical methods to enlarge negatives Computer-generated enlarged negatives

Of these, I will discuss only the in-camera negative. While photomechanical enlargement methods are still practiced by experts in their field,’ this tech- nique has generally given way to the making of computer-generated enlarged negatives. (See Appendix E: Crafting Digital Negatives for Contact Printing Platinum and Palladium.) FIGURE B.1 Tkt 5 x 7 sud 12 x LO Ivtk C~MERAS(A 35 MM CAMERA IS IIL( LIldEd fOR 5CAlt )

THE CAMERA.EXPOSEDNEGATIVE experience before letting yourself be tempted to move to 8 x 10 or the “Ultra-Large’’ cameras. It would be TO directly expose the negative in the camera, the actual better to spend the extra money on a transmission size of the image to be reproduced must be taken into densitometer. Most likely, once you form an attach- account. While effective prints can be made from ment to the half-frame, you may not want to discard it medium format cameras, including 120 roll film, many (Figure B.1). photographers will find the large format view camera to be most ideal. In addition to the increased image size and authenticity, sheet film allows for individual processing. THE ULTRA~LARGEFORMAT For those who have a strong back and a weak mind, CAMERASIZE as I do, and who might have an interest in the ultra-large format, a brief description follows. Most cameras of In considering the format of a first view camera, my this nature are related to the standard sizes of the personal recommendation for PdPd printing would banquet cameras used 80 to 100 years ago. Due to the be to skip the 4 x 5 inch format in favor of the S x 7. low resolution of camera and enlarging lenses of that Most 4 x 5 cameras sold are actually 5 x 7 sizes with time, when large groups of people were photographed (at a reducing back. The 5 x 7 format is a cousin to the a banquet, for example), their features were not English “half frame” used by early photographers to recognizable in the final enlarged print. Therefore, produce many of the platinum prints we see in museum a negative was needed that was large enough to be collections. If S x 7 is found to be impractical, or if contact-printed at the size desired. It was also preferable you wish also to make silver gelatin prints via the more that it be formatted to accommodate the usual grouping ubiquitous 4 x 5 enlarger, all 5 x 7 cameras come with of the subjects. Consequently, the long rectangles of a 4 x S reducing back. the banquet camera format were developed and per- Since practically all difficulties in working with sist to this day. They are: 7 x 17,s x 20,12 x 20,4 and to larger cameras are exponentially related to the size of a lesser extent, 14 x 17 inches. Many original examples the format, I would also recommend at least a few years made by Korona and Folmer Schwing still exist and are used today. Several manufacturers will make a new Palladium Negative, you will note that there may easily camera on special order (see Sources). Film holders’ be a dozen different processing requirements, particu- can also be ordered. Film is available in special-order larly from a project that involves extended time away quantities. (See Appendix C: Some FilmDeveloper Com- from the lab. Having one box for each development time binations to Produce a Platinudalladium Negative.) or concentration could require 10 to 12 boxes to arrange in the dark for film transfer.6 The following is a method that I devised during ORGANIZATIONOF EXPOSED FILM my many projects that took me away from my lab for periods of 4 to 8 weeks. I carry two sets of 12 film When away from their labs, few view camera photo- holders. I label them with Roman numerals I (red) and graphers develop sheet film while “on the road.” Most I1 (blue). Each side of a film holder is given an Arabic have devised a system of organizing their latent images number from 1 to 12. Therefore, each sheet of film is in boxes after removal from the film holders. As each identified: 1-1, 1-2, 1-3 to 1-12, and 11-1, 11-2, 11-3 to 11-12. sheet may require a specific development, it is important Following the numbers in sequence, I expose two sides that it be properly identified when removed from the of a film holder identically and record all data, including box for processing. development time and concentration of developer. Many Zone System photographers carry boxes I mark one side with :’ for first development. This may marked, N, N + 1, N - 1, and so on, depending on the be side 1 of a holder, leaving side 2 for later develop- variance of light conditions they encounter. ment. This sequence may change if one exposure is felt Referring to the next section, Appendix C: Some to be inferior to the other. For example, I may expose FildDeveloper Combinations to Produce a Platinum/ one side only to find a busload of tourists swarming

.’.Note that the Korona and Folmer Schwing cameras and their descendants do not take the same type of film holders. With Folmer ‘. A particularly valuable accessory for the traveling view camera Schwing, the light trap is a slot; with Korona it is a positive ridge. photographer is the Harrison Film Changing Tent. It is basically Better yet, your camera back should he at hand when the film holders a scaled down version of a North Face tent with external collapsible are made, or vice versa. Never take any view camera in the field nylon supports. Two ports for the arms allow the photographer to without first giving it the “flashlight test,” wherein a flashlight is change film in a light tight environment. Sizes vary from the “Pup” placed in the camera, with holders inserted. After two minutes in tent (26 x 19 x 12 inches), to the Jumbo sizes for ultra large film up a totally dark environment, a bad fit as well as other light leaks can to 12 x 20. The Jumbos have optional “chutes” at each end to store be detected by the slits of light escaping from the camera. At the film hoxes and film holders out of the way when not being accessed. same time, by removing the dark slide you can check the light traps. (Source: any photographic supplier.) 154 APPENDIXB

TABLE B. 1 SEQUENCES Of DEVEIOPIN~SkEETS Of FILM fROM stack and developed. The numbers are crossed A SEl Of TUE[\E out (&, 5. 9). The six sheets (or more if there are more sets First Phase Second Phase Last Phase of 12) are dried and read with a transmission 1-1-1 l+l- densitometer. Modifications in development, 2"+2 if necessary, are made for the second set of six. 3+2+2 2- 1 4"+3+3 SECONDPHASE S*+S 6+4-3 3-3 The remaining sheets have become Nos. 1, 2, 7"+5+5 3, 4, 5, and 6. In this example, Nos. 1, 3, 8-6-4 4+2 and 6 are to be processed the same way. 9:1+9 They are pulled for development and crossed 10-7-5 5-3 out (4,3, 6). 11-+8+6 6-6 12"+ 9- 9 LASTPHASE A new set of numbers, 1, 2, and 3 remain. around my camera before I can do the second. I will Nos. 1 and 3 are removed and processed, expose it anyway and mark it " for first development. leaving No. 2, which has become No. 1. That I wait until the entire set of 12 has been exposed is processed last. before transferring the film to a box (the original film Having a "second chance" at developing each image box with three covers). I arrange the holders with the allows for fine tuning. For example, if I am going for No. 12 on the top following sequentially to No. 1 on the a negative density range (DR) of 1.80, there is little bottom. In the dark, I transfer each sheet, one at a time, room for error. If the first negative reads 2.0 or 1.6, to the box. Therefore, the film is finally oriented with I can slightly modify the development for the second. No. 1 on the top and No. 12 on the bottom. The box (See Appendix C: Some FilmDeveloper Combinations is labeled and sealed with tape. The next box, containing to Produce a Platinum/Palladium Negative.) If both unexposed film, is emptied when that film is transferred negatives are suitable for printing, I store one set in to the film holders. That becomes the box to receive the another location. (See Chapter 10: Advanced Technique.) next set of exposed film. In the lab, I will start developing the films marked '-. When they are removed from the stack of twelve, the PROCESSINGTHE LARGENEGATIVE remaining films are in a new sequence, again numbered with No. 1 on the top and on down to the bottom. Large sheet film negatives can be processed individually I work in phases. (Table B.l) Note that each single or in small sets of no more than six. A number of choices side of a holder has been marked '-for first develop- are available: ment. In the dark, the sheets of film are easily "fanned" Tray so that I can count down from the top to identify and Rotary processing: remove all films that will receive the same processing. (I wear Latex gloves under cotton gloves. I use my Drum (JOBO' ) teeth to remove the cotton -gloves before processing.) BTZS tube development Table B.l shows some examples of the workflow. Film holdedopen tank Daylight plastic tanks FIRSTPHASE Recently, rotary systems of development (and print 0 Film sheets Nos. 2+, 5*,and 9" are removed and processing) have gained in popularity. There are con- developed. They are crossed out (2.4.9). siderable advantages: 0 The remaining film is numbered in a new sequence (second column). It is primarily a closed system, minimizing skin or Films No. 4", 7", and 12'krequire a different time respiratory contact with chemicals. or concentration than the first three. They have Although film must be loaded in the dark, become 3, 5, and 9. They are removed from the processing is done in normal room light. Smaller amounts of solutions are used. lightly covered with silicon. Too much silicon will grease Since processing is done in a water bath, precise the hands to the point that wet film cannot be held temperature control is possible. securely. As the entire surface of film is in equal contact Surprisingly, little information is available in the with developer, mottling or uneven development literature adequately covering this most basic of photo- is less likely. graphic procedures. Therefore, I present the following Sheets of film do not contact each other, reducing as my recommended method: the chance for scratches. 1. Prepare trays of developer, stop bath, and fixer. Multiple sheets of film can be processed utilizing To prevent the uneven development of edges by larger tanks. splash back, choose trays at least one size larger Nevertheless, tray processing is still practiced by the than will accommodate the film. Darkroom mod- majority of large format photographers and is unlikely ifications such as space heaters, coolers, or water to be displaced in the near future for the following baths may be utilized if the area is subject to air reasons: temperature changes. If a presoak’ is desired, add an additional tray of distilled water that is the same It is simple and dependable. temperature as the developer. Set the clock for the It is less expensive. A mechanized rotary system indicated development time. can cost more than $l,OOO.OO.’ Tray processing can more easily be done in A mechanical tray agitation system is made by alternative spaces, such as a kitchen or bathroom. Trays take less storage space. Edwards Engineering. (Source: EE) Although ultra-large film can be rotary processed, If the pungent odor of the acetic acid stop bath the monstrous size and expense of the drums and is bothersome, other alternatives exist. See Anchell’s tubes make it impractical. Also, uneven develop- Darkroom Cookbook, or purchase the TS-4 stop bath ment in sizes greater than 11 x 14 has been reported. from Photographers’ Formulary or Clayton’s “odor- free” stop bath and fixer from a photographic supplier. 2. Lay out the film holders and put on the gloves before turning off the light. I use cotton gloves TRAY PROCESSING whenever handing film. In this case, it is advisable to Since the majority of readers will, at least initially, place cotton gloves temporarily over the latex gloves tray process, I will present this procedure first. This is until just before the film is immersed. You can my choice,’ partly because it is most amenable to my remove the cotton gloves with your teeth. ultra-large format photography. In experienced hands, 3. If more than one sheet is to be processed, hold the there is little chance of uneven development or scratching. film as a deck of cards. Immerse one at a time, For tray development, the use of latex gloves is emulsion side up, either in developer or presoak, recommended. Regardless of any opinions about the allowing each to become somewhat moistened. relative toxicity of photographic chemicals, it is best that Set the clock and immediately separate the film. hands not be immersed in any solution constantly for multiple periods of 20 to 30 minutes. Also, gloves give I prefer not to have more than two sheets an added advantage of shielding the softened emulsion stacked at a time. If more sheets are to be processed, surfaces from fingernails and rough skin particles. When choose a tray that will hold two, four, or six sheets of you are choosing latex gloves, first determine whether film spread across the bottom. Purchase 2-inch suction or not you have an allergy to latex. It is quite common. cups used for window decorations from a party store. Most disposable gloves come lubricated, either with Be sure they have a small hole at the nib. Remove powder or silicon. Each brand differs. Look for gloves the metal hook and cut a wooden cotton applicator

’. In matters of size and expense, BTZS Tubes are compact and relatively inexpensive. They are an economical alternative to the 9. If more than one sheet is included in a tray, a presoak in distilled mechanized rotary processors. See View Camera Store (VCS) in water will lessen the chances of film adhering in the developer. It also Sources. facilitates even absorption of developer into the film emulsion. Most *. Tray processing is also the choice of Bob Herbst for the processing of photographers add 30 seconds to the development time to allow for pyro negatives. (See Appendix D: Pyro and Platinum Printing.) replacement of water by the developer. 156 APPENDIXB midpoint in the shaft. Insert the wooden end in the to be stored when not in use. When functioning, it must hole opposite the suction area with the cotton end be attached to running water and a drain. Individual protruding. Moisten the suction cups and place them drums must be purchased based on film or print size.” to serve as dividers in the tray. When solution is added, Detailed instructions come with purchase. For a single sheet of film is placed in each “compartment.” processing sheet film while working in the dark, the If properly done, the film should move freely without negatives are inserted along slots into a cylindrical touching. The cotton tips prevent scratching of the base drum. Drum designs allow for single or multiple films to side of the film. Similar dividers can be placed in the be processed simultaneously. Following placement of the trays for stop, fix, and wash. This method is particularly cap, processing is done in room light. Solutions are useful for developing two sheets of 7 x 17 film placed injected into and drained from the drum, which is side by side in the same tray. constantly revolving in a temperature-controlled water bath. Washing and drying are done by conventional ’ . Another option is a manufactured tray: The means. “Slosher,” a dipping mechanism based on the fast-food process of deep frying food. (Source: SL) The negatives are placed in separated compartments and “dipped” BTZS TUBES into the developing solutions. Originated by Phil Davis, BTZS Tubes are now 4. During the first minute, agitate vigorously with marketed as BTZS‘ Film Tubes by View Camera Store constant jarring to dislodge air bubbles. Following (VCS).l’ They come is sizes from 4 x 5 to 8 x 10, as this, the cycle can be slowed. After two or three well as odd sizes of 4 x 10, 7 x 17, 8 x 20, and 12 x 20 minutes, allow the film to remain still for 30-second (Figure B.2). Other BTZS products include: periods. At each interval, lift the film from the tray Plotter Program’@:A computerized program for and drain for at least two seconds. Agitate for the plotting and analyzing film and paper first five seconds following reimmersion. Halfway data for personalized metering and development through the development period, rotate each sheet techniques 180 degrees for the remaining time. Portable computer programs: Software for prac- i Landscape photographers may wish to consider tical use of personalized data in the field, either the following: Whether oriented horizontally or verti- with PC6 or Palm Pilotm computers. The cally, the notch is always in the area occupied by the sky. PowerDial‘ is a fabricated, noncomputerized When touching the film, use the opposite corner. Any guide to film exposure in the field. fingerprints or abrasions will most likely end up in the BTZS development tubes containing detailed foreground. instructions. Their use is also completely dis- 5. When the developing time is up, drain and transfer cussed in Beyond the Zone System (Davis, 1998). film immediately to the stop bath. If the developer The original “tubes” were PVC pipe with a seal at is to be reused with replenisher, take care not to one end and a removable cap at the other. Now they are introduce stop bath into the developer tray. commercially manufactured to last a lifetime (and most 6. Follow the manufacturer’s instructions for fixing, likely that of your heirs as well). Hypo Clearing Agent or Hypo Eliminator, and wash. 1. Working in a lighted wet space, a measured 7. After the wash cycle, rinse vigorously and place the amount of developer is placed in a threaded cap, film in distilled water into which the recommended which is placed upwards in a water bath of a amount of Photo-flo@ has been added. Sponge both surfaces in the soak, as well as after the sheet is hung lo- Another JOBO‘ disadvantage is that all films in a cycle will be to dry. developed the same. While this may be useful for those doing panoramas or other projects that require identical development, many view camera workers will specify a different time and/or concentration DRUMPROCESSING for each single sheet of film. The BTZS tubes allow for this choice. The advantages of a drum (JOBO“) processor have been ‘I. About BTZS: Phil Davis published the first edition of Beyond the Zone System in 1981. A fourth edition is now available from Focal listed. Although for many purposes it may be the Press (see Bibliography). The View Camera Store is now marketing preferred method, it is hardly an absolute necessity for a number of his inventions, along with scheduled workshops. (Source: the hobbyist. The actual unit is bulky, but light enough VCS) containing the developer. The new cap is still oriented down, so no developer has yet entered the tube. 4. The rest of the process can be done with the lights on. 5. In the wet space, the sealed tubes are turned cap up and agitated to allow the developer to contact the film. They are “log rolled” in a tray of temperature- controlled water (usually 70 or 75” F). 6. When the developing time is up, in rapid motions, without turning off the lights, the cap is quickly removed, the developer is discarded, and the tube is immersed in a tray of stop bath. 7. Immediately remove the film from the tube while it is in the stop bath. The film is now ready for traditional tray fixing, clearing, and washing. While in the fixer, to avoid scratching, I transfer the film to film hangers for the rest of the steps.

FILM HANGER/OPENTANK The use of film hangers is well described in Kodak’s Kodak Professional: Black-and-white Films (1998). Some problems inherent with tank development should predetermined temperature. The x sizes come 4 5 be considered. The tanks take a significant amount of with a customized tray, containing receptacles to solution: 1 gallon for 4 x 5 or 5 x 7 sizes. The perforated hold the caps in the water bath. sides of the holders are notorious for producing uneven In a dark space, the film is rolled and placed 2. scalloping at the edges of the negative. Unless one is lengthwise into the tube, emulsion side to the equipped with a nitrogen burst system, this method interior. Another dry threaded cap is placed on the should be used with care. end. Mark the development time on masking tape and stick it to the tube. As each tube will be removed from the developer and fixed individually, DAYLIGHTPLASTIC TANKS it is possible to develop as much as six sheets at different times. I absolutely do not recommend daylight plastic tanks. 3. Again, turn off the lights and hold the tube cap side The disadvantages listed for tank development are down; the cap is removed and replaced by the cap multiplied to unmanageable levels. Thispageintentionallyleftblank 159 160 APPENDIX C

Based on my personal experience and studies from 7 x 17 and up may be impractical. For this reason, Phil Davis’ Plotter Program” I recommend the follow- developing times for 320TXP, FP4 plus, HP5 plus Classic ing filddeveloper combinations as a starting point to be 400 are given for tray development. See Table C.l for further refined by testing and work in the studio and some suitable films for the platinudpalladium (PtPd) field.’ In the making of platinum or palladium negatives, process and format sizes available. the choice of the film and developer is largely dependent The very popular Kodak TMX film has been upon the characteristics found in the Family of Curves renamed 100Tmax. 1OOTmax most recently has come produced by each combination. with a ultraviolet (W)light blocker, making the film totally inappropriate for any printing process using W The Family of Curves expresses the differences in light for exposure. EFS (Effective Film Speed) and the slope of the curve (average gradient) when the film is subjected to varying times and concentrations of development. This is dis- CHOOSINGA FILM cussed more thoroughly in Part Two: Sensitometry for the PlatinumiI’alladium Process (Chapters 12 and 13). Available only in 4 x 5 and 8 x 10 sizes A platinum or palladium negative must be given Very stable EFS and little reciprocity failure considerably more development to reach the steepness Straight curve with little dip in shadow values of curve necessary to produce sufficient contrast. With (belly) many filddeveloper combinations, a limit is reached- Quite sensitive to inaccuracies in development a Gamma Infinity, where more time or concentration of times developer does not increase the slope, but simply raises Medium rise in base + fog (B+ F) with higher shadow and highlight densities equally. This is found development in many fine-grain films and compensating-type de- Family of curves very responsive to development velopers, neither of which is suitable for a platinum or changes palladium negative. 400Tmax developed in D-76 1:1 may be the most The combinations I have chosen here include films appropriate filddeveloper combination for PtPd of IS0 between 100 and 400 that have been developed photography in solutions of sufficient “energy” to produce a family of curves applicable to our process. In many cases, two or more dilutions of developer are given to cover the DELTA100 extremes of subject brightness range (SBR). The izumbers ody serve as a starting point and will require nzodifi- Available only in 4 x 5 and 8 x 10 sizes cation based on your personal practices of metering and Relatively stable EFS and moderate reciprocity development techniques. Later, you may discover other failure combinations that are more suitable to your needs. Medium rise in B+F from higher development Generally, those with medium-format cameras Straight curve with little dip in shadow values (2 114 to 4 x 5 inches) can use the slower speed films. A good substitute for 1OOTmax sheet film, which For cameras 5 x 7 and larger, due to the smaller no longer can be used in the PdPd process apertures required for depth-of-field focus, the 320 to 400 IS0 films may be more appropriate. At the time of the publication of this book, the EFKE 100 users of ultra-large format find their choices limited. Available in all popular sizes Moreover, while rotary development techniques are Very responsive to development changes gaining in popularity, their uses for film sizes from Stable IS0 with extreme development changes Straight curve with little dip in shadow values Another good substitute for 100Tmax sheet film, which no longer can be used in the Pt/Pd process Note that negatives in the 1.4 density range (DR) or higher are also required for the nonsilver processes of Cyanotype, Kallitype, Carbon, Although available in ultra-large sizes, the 100 Bromoil, and others. The information contained in this section can be IS0 makes it difficult to manage with small lens readily adapted for those processes. apertures Film 4x5 4x10 5x7 8x10 7x17 Sx20 11x14 12x20 16x20 12x24

Kodak 400Tmax 50 50 Kodak 320 TXP 50 50 50 10' 25* 25' 25' 25" Ilford 125 FP4f 251100 25 25 25 25 25 Ilford 400 HP5+ 251100 25 25 25 25 25 25 25 25 Ilford 100 Delta 251100 25 Bergger 200 BPF 25 25 25 25 25 25 25 25 25 25 Eke 100 PL 50 50 50 25 25 50 10 10 10 J & C 200 Classic 25 25 25 25 25 25 25 J & C 400 Classic 25 25 25 25 25 25

*These Kodak films are available only by purchasing a minimum order, usually in the range of $lS,OOO.OO! Also, the very popular TMY (now 400Tmax) in the 5 x 7 size has been discontinued. At this time, the Kodak films 400Tmax and 320 TXP still are most suited for the PtPd process. Nevertheless, it may be prudent to become familiar with films from other manufacturers, particularly if you work in 5 x 7. Considering the current Kodak business practices, any or all of their sheet films may disappear overnight!

Efke and Classic films are manufactured in Considerable reciprocity failure Eastern Europe and can be ordered directly online. Little increase in B+F with overdevelopment (Source: /C) Distinct rise in highlight portions of the curves compliments the extended toe of the platinum FP4 PLUS and palladium print Family of curves very responsive to development Available in all popular sizes, including ultra- changes large format Relatively stable EFS and moderate reciprocity failure 320 TXP has replaced Kodak TXT. Our Medium rise in B+F from higher develop- studies have shown it to have basically the same ment characteristics as the older TXT; however, more Straight curve with little dip in shadow development energy is needed to reach the required values negative contrast. The newer TXP does not appear to Low IS0 makes it problematic for ultra-large have the drastic alteration of IS0 with development format photography change as noted with the older TXT. This information is represented in the following filddevelopment tables.

HP5 PLUS , Despite the drawbacks, 320 TXP is my choice for Available in all popular sizes, including ultra- my 7 x 17 and 12 x 20 cameras. The changes in EFS and large format reciprocity failure are easily calculated in the field using Straight curve with little dip in shadow values BTZSF computer programs or the PowerDial" available Relatively stable EFS and moderate reciprocity from Darkroom Innovations. failure Considerable rise in B + F from higher develop- ment (between 0.2 and 0.3) BERGGER200 BPF Expansion development over SBR 5.6 (N 1) + Available in all popular sizes, including ultra- is difficult large format Basically unresponsive to changes in 320 TXP time and/or concentration using traditional Available in all sizes developers Minimum order required for ultra-large film sizes Popular with photographers using pyro Dip in shadow values (belly) causing some EFS formulas (See Appendix D: Pyro and Platinum changes Printing.) 162 APPENDIXC

CLASSIC400 TABLE c.2 T~VEFIIM/DEVEIOPER ANd TEMPERATURECOM~INATIONS

Available in all popular sizes, including ultra- Tubell0 B 0' Development Constant Agitation large format May be logical choice for ultra-large format Film IS0 Developer Temperature photographers who cannot handle the minimum EFKE 100 D-76 70°F order required for Kodak films DELTA 100 100 D-76 75°F Somewhat unresponsive to increases in develop- FP4 PLUS 125 DDX 70°F ment required for low SBR TMY 400 D-76 70°F HP5-t 400 D-76 70'F 320 TXP 320 D-76 70°F TWELVEFILM/DEVELOPER COMBINATIONS Classic 400 400 D-76 70°F

Table C.2 lists 12 filddeveloper combinations2 for your Tray Development Intermittent Agitation consideration. Film IS0 Developer Temperature

FP4 PLUS 125 D-76 70°F E F F ECT I v E F I LM/ DEVE LOPER CoM B I NAT Io Ns TXT 320 D-76 70' F HPS PLUS 400 D-76 70°F FOR SELECTIVEPROCESSING OF PLATINUM Classic 400 400 D-76 70°F AND PALLADIUMNEGATIVES

The following data is based on my personal experience and is analyzed from Plotter Program@ data. Special thanks to Phil Davis, Keith Schreiber, and View Camera DR 1.8: the extreme contrast for Nos. 1, 2 Pd Store. using the Ratio Method DR = density range DR (LogE)= 1.40, 1.60, and 1.80 SBR = subject EFS =effective film speed ROTARYOR TRAY DEVELOPMENT: brightness range Generally, the choice of tray or tube/JOBO" is For those using the Zone System, see Chapter 3: based on personal preference, laboratory space, The Negative, for correlations with SBR readings and negative size. If one set of data is to be used Film/developer combinations are listed for two for the other method, tray to tube/JOBO proces- methods of processing: sors or vice versa, the following should be Tube or JOBO"-constant agitation at 70°F factored in: Constant agitation and/or higher Tray-intermittent agitation at 70°F temperatures used with tube/JOBOg' result in shorter development times. To convert from tray Developing times and/or concentrations are given to tube/JOBOB, subtract 15 to 20% from the for: development times. For the reverse, add 10 to DR 1.4: the mid-range contrast for No. 7 PtPd 15%. These conversion factors are only approx- using the Ratio Method and No. 5s using the Na2 imate. For accurate development times, analysis Method of the average gradients of specific films, devel- DR 1.6: the mid-range contrast for No. 7 Pd opers, and methods are necessary (Davis, 1998). using the Ratio Method This is outside the scope of this text. Note that in many cases, it is desirable to change dilutions rather than time. For tray development, times are best kept over 5 minutes, so higher '. Film developers for the Pt/Pd process must have the energy to dilutions may be necessary with high SBR. With increase the slope of film curves with minimal effect on B+F. D-76 drums or tubes, development times of 3 to 4 (Ilford ID1 1) meets these requirements. It is simply compounded from readily available chemicals and is available throughout the world. For minutes are possible. this reason, D-76 is the developer of choice for the following film/ When you dilute more than the recommended developer combinations, either at a 1:l dilution or straight. concentration of developer in a tray, add more solution to keep the same amount of active DATA ingredient available. Note that for PtDd negatives, an “N + 2” TUBE/J 0 BO@ DEVELOPMENT development may only be obtained special by The reader is welcome to communicate with me via processing: heating of developer, high energy email regarding other filddeveloper choices. I can be developer, or selenium toning. reached at: Effective Film Speed is calculated to the nearest Dick. [email protected] 1/3 value.

TABLE C.3 DELTAI00 ANd D-76

Film: DELTA 100 Developer 0-76 Temperature 70“ F Sheet Film Tube Development Constaizt Agitation Time in Minutes ZONE DEV SBR EFS DR CONCENTRA TI0N

STR 1:l N 7 100 1.4 7 10 100 1.6 8 13 100 1.8 10.5 16 - 6 100 1.4 8.5 13.5 12s 1.6 11 16 12s 1.8 13.5 20 N+l 5.6 100 1.4 10 12s 1.6 12 12s 1.8 15 N+l 1/2 4.2 125 1.4 15.5 12s 1.6 20 12s 1.8 k - 8 80 1.4 8 100 1.6 10 100 1.8 12 N-1 8.6 80 1.4 7 80 1.6 9 100 1.8 10.5 N-2 10.5 so 1.4 5 64 1.6 6.5 80 1.8 7.5 N-3 12 50 1.4 4 64 1.6 5.5 64 1.8 6.5

*May need selenium toning to reach this film curve gradient. (See Chapter 3: The Negative.) 164 APPENDIXC ~

TABLE C.4 Efkt 100 ANd D-76

Film: Efke 100 Developer 0-76 Temperature 70"F Sheet Film Tube Development Constant Agitation Time in Minutes ZONE DEV SBR E FS DR CONCENTRATION

STR 1:1 N 7 100 1.4 6.5 8.5 100 1.6 8.5 11 100 1.8 10.5 14.5 - 6 125 1.4 8.5 11.5 125 1.6 11 15 125 1.8 12 20 N+l 5.6 125 1.4 9.5 13 125 1.6 11.5 16 125 1.8 13.5 N+l 112 4.2 125 1.4 14 125 1.6 16 125 1.8 20 - 8 100 1.4 7.5 100 1.6 9 100 1.8 11.5 N-1 8.6 100 1.4 7 100 1.6 8 100 1.8 10 N-2 10.5 80 1.4 5.5 80 1.6 7 80 1.8 8 N-3 12 80 1.4 5 80 1.6 6 80 1.8 7 TABLE C.5 FP4+ md DDX

Film: FP4+ Developer DDX Temperature 70F Sheet Film Tube Development Constilnt Agitation Time in Minutes ZONE DEV SBR EFS DR CONCENTRATION

1:2 1:4 1:6 N 7 125 1.4 4 6 11 125 1.6 5 7.5 15 125 1.8 7 10 - 6 125 1.4 5.5 8 15 125 1.6 7 10.5 125 1.8 10 16 N+l 5.6 125 1.4 6 11 125 1.6 8 18 125 1.8 12 - 5 125 1.4 7.5 125 1.6 11 125 1.8 it N+l 112 4.2 125 1.4 12 125 1.6 20 125 1.8 i 8 100 1.4 8.5 100 1.6 6 11 125 1.8 7 14 N-1 8.6 80 1.4 7 100 1.6 9.5 100 1.8 12 N-2 10.5 80 1.4 5 80 1.6 6.5 100 1.8 7.5 N-3 12 64 1.4 4.3 80 1.6 5.5 80 1.8 6.6

“May need selenium toning to reach this film curve gradient. (See Chapter 3: The Negative.) 166 APPENDIXC

TABLE C.6 400TMAX ANd D-76

Film: 400Tmax Developer 0-76 Temperature 70°F Sheet Film Tube Development Constant Agitation Time in Minutes ZONE DEV SBR E FS DR CONCE NTRATI0 N

STR 1:l N 7 400 1.4 7 12 400 1.6 8 13.5 400 1.8 9 15.5 - 6 400 1.4 8 14 400 1.6 10 16 400 1.8 11 N+1 5.6 400 1.4 9 15 400 1.6 10 400 1.8 12 - 5 400 1.4 10.5 400 1.6 13 400 1.8 20 N+l 1/2 4.2 400 1.4 20 400 1.6 400 1.8 b - 8 400 1.4 10 400 1.6 11.5 400 1.8 13 N-1 8.6 400 1.4 9.5 400 1.6 10.5 400 1.8 12 N-2 10.5 320 1.4 7.5 320 1.6 8.5 320 1.8 9.5 N-3 12 250 1.4 6.5 250 1.6 7.5 250 1.8 8.5

‘May need selenium toning to reach this film curve gradient. (See Chapter 3: The Negative.) TABLE C.7 HP5+ ANd D-76

Film: HPS+ Developer 0-76 Temperature 70°F Sheet Film Tube Development Constant Agitation Time in Minutes ZONE DEV SB R E FS DR CONCENTRATION

STR 1:1 N 7 400 1.4 8.5 14 400 1.6 11 17 400 1.8 15 - 6 400 1.4 11 17 400 1.6 15 400 1.8 20 N+l 5.6 400 1.4 13 400 1.6 16 400 1.8 x- - 5 400 1.4 16 400 1.6 20 400 1.8 .+ N+l 1/2 4.2 400 1.4 20+' 400 1.6 x- 400 1.8 x- - 8 400 1.4 11 400 1.6 14 400 1.8 17 N-1 8.6 400 1.4 10 400 1.6 12 400 1.8 15 N-2 10.5 320 1.4 7.5 320 1.6 12 320 1.8 15 N-3 12 250 1.4 6.5 320 1.6 7.5 320 1.8 9

'May need selenium toning to reach this film curve gradient. (See Chapter 3: The Negative.) '20+ = 20 minutes in developer heated to 85°F. 168 APPENDIXC

TABLE C.8 C~ASIC400 ANd ID1 1

Film: Classic 400 Developer ID 1 1 Temperature 70"F Sheet Film Tube Development Constant Agitation Time in Minutes ZONE DEV SBR EFS DR CONCENTRATION

STR 1:1 N 7 400 1.4 6.5 14 500 1.6 8.5 19 500 1.8 16 - 6 500 1.4 9 20 500 1.6 1.8 N+l 5.6 500 1.4 10.5 1.6 1.8 - 5 640 1.4 16 1.6 1.8 - 8 320 1.4 10.5 400 1.6 6.5 14 500 1.8 8 19 N-1 8.6 320 1.4 8 320 1.6 5.5 12 400 1.8 7 15 N-2 10.5 250 1.4 6.5 320 1.6 8 320 1.8 5 10.5 N-3 12 200 1.4 5 250 1.6 6.5 320 1.8 8 TABLE C.9 FP4+ ANd D-76

Film: FP4+ Developer 0-76 Temperature 70°F Sheet Film Tray Development Intermittent Agitation Time in Minutes ZONE DEV SBR EFS DR CONCENTRATION

STR 1:1 N 7 125 1.4 8 10 125 1.6 12.5 15 125 1.8 15 19 - 6 125 1.4 13 17 125 1.6 16 20 125 1.8 20 Nfl 5.6 125 1.4 14 18.5 125 1.6 19 125 1.8 20++ - 5 125 1.4 18 125 1.6 20++ 125 1.8 Nfl 1/2 4.2 125 1.4 125 1.6 125 1.8 - 8 100 1.4 7.5 125 1.6 10.5 125 1.8 15 N-1 8.6 100 1.4 7 100 1.6 8 100 1.8 13.5 N-2 10.5 100 1.4 5.5 100 1.6 6.5 100 1.8 7.5 N-3 12 100 1.4 4.3 100 1.6 5.5 100 1.8 7

"May need selenium toning to reach this film curve gradient. (See Chapter 3: The Negative.) '201 = 20 minutes in developer heated to 85°F. 170 APPENDIX C

TABLE C.10 HP5+ ANd D-76

Film: HP5 + Developer 0-76 Temperature 70"F Sheet Film Tray Developmetit Intermittent Agitation Time in Minutes ZONE DEV SBR EFS DR CONCENTRATION

STR 1:1 N 7 400 1.4 9 16 400 1.6 12 20 400 1.8 15 - 6 400 1.4 12.5 20 400 1.6 15.5 400 1.8 20 N+1 5.6 400 1.4 13.5 400 1.6 18 400 1.8 .+ - 5 400 1.4 16 400 1.6 20 400 1.8 i N+1 1/2 4.2 400 1.4 > 400 1.6 400 1.8 - 8 400 1.4 15 400 1.6 16 400 1.8 19 N-1 8.6 400 1.4 14 400 1.6 15 400 1.8 16 N-2 10.5 320 1.4 11.5 320 1.6 13.5 320 1.8 14.5 N-3 12 320 1.4 10 320 1.6 12.5 320 1.8 13.5

*May need selenium toning to reach this film curve gradient. (See Chapter 3: The Negative.) TABLE C.l 1 720 TXP ANd D-76

Film: 320 TXP Developer 0-76 Temperature 70°F Sheet Film Tray Development Intermittent Agitation Time in Minutes ZONE DEV SBR EFS DR CONCENTRATION

STR 1:l N 7 320 1.4 9 16 320 1.6 10 19 320 1.8 11.5 - 6 320 1.4 11.5 20 320 1.6 14 100 1.8 20 NS1 5.6 320 1.4 11.5 320 1.6 17 320 1.8 * - 5 320 1.4 20 320 1.6 20+t 320 1.8 20ft N+I 1/2 4.2 320 1.4 20f' 320 1.6 * 320 1.8 * - 8 320 1.4 12.5 320 1.6 15 320 1.8 18 N-1 8.6 320 1.4 11 320 1.6 12.5 320 1.8 15 N-2 10.5 320 1.4 7.5 320 1.6 9.5 320 1.8 11.5 N-3 12 250 1.4 6 250 1.6 7.5 320 1.8 9 N-4 14 200 1.4 5 250 1.6 6 250 1.8 7

*May need selenium toning to reach this film curve gradient. (See Chapter 3: The Negative.) '2O+ = 20 minutes in developer heated to 85°F. 172 APPENDIX C

TABLE C.l 2 CIAssic 400 ANd D-76

Film: Classic 400 Developer 0-76 Temperature 70" F Sheet Film Tray Development Intermittent Agitation Time in Minutes ZONE DEV SB R EFS DR CONCENTRATION

STR 1:1 N 7 400 1.4 7 13.5 500 1.6 8.5 20 500 1.8 16 - 6 500 1.4 9 20 500 1.6 16 1.8 Nfl 5.6 500 1.4 10.5 1.6 1.8 - 5 1.4 16 1.6 1.8 - 8 320 1.4 10.5 400 1.6 6.5 13 500 1.8 8 20 N-l 8.6 320 1.4 9.5 320 1.6 5.5 11.5 400 1.8 7 15.5 N-2 10.5 250 1.4 6.5 320 1.6 8.5 320 1.8 10.5 N-3 12 160 1.4 5 250 1.6 7 320 1.8 8 APPENDIX D

Bob Hevbst

PLATE D.l HEA~IN tiwds 2003 12 x 20 INCk PriPd (Lo Bob HERbST)

173 174 APPENDIXD

Pyro, also known as pyrogallol or pyrogallic acid, In order to demonstrate how this concept also has been used as a developing agent for film for well applies to black and white films processed in traditional over 100 years. Boxes of glass dry plate negatives from and pyro developers, I contact printed the 4 x 5 Stouffer the late nineteenth century often came with a “pyro- step tablet onto several sheets of 4 x 5 TMAX 400 film soda” formula pasted on the front of the box. Pyro is with identical exposures. I processed the film in D-76 a staining developer, meaning its developing action and my standard WD2D pyro formula. The goal was to stains the reduced silver in proportion to the amount produce a reversed image of the step tablet. The Stouffer of silver reduced in the negative. The color of the stain step wedge and the pyro negative are shown in Figures can vary from brown to yellow to green depending on D.2 and D.3. which formula is used. There are a number of variations The chart in Figure D.4 shows the results for the of pyro formulas, including ABC, John Wimberley’s D-76 negative. As with the Stouffer step tablet, the WD2D, Gordon Hutchings’ PMK, and Rollo-Pyro. Pyro density readings for red, green, and blue channels are has been used throughout the history of photography. virtually identical. The slight offset between the black Pyro formulas were included in U.S. military manuals and white readings and color readings is likely due to for field photography during the World Wars. Many calibration drift on the black and white densitometer, anecdotes, claims, and lore about pyro exist. It has been since all other measurements yielded similar values for praised as having “mystical qualities” that ensure a the red channel and the black and white. perfect print and cursed by those not used to its effects The next step was to read the densities of the pyro in platinum printing. negative with the same densitometers and also with an X-Rite 361T densitometer. The 361T is a model used in the graphic arts and printing industries, and it has a “UV channel.” It is therefore capable of measuring THE SENSITOMETRICEFFECTS OF PYROSTAIN: density presented to ultraviolet (W)light. The graph “ S PECTRAL D ENs ITY” of the pyro negative in Figure D.5 tells a very different story. There is a pronounced divergence of the data for In order to fully comprehend the role and behavior of the red, green, blue, and W filters, clearly showing the pyro stain in platinum printing, you must understand additive effect of the stain in total negative density as the how the stain affects light passing through the negative. color of the light changes from red to ultraviolet. Traditional developers create an image on film by Because pyro stain has color, it behaves like a filter reducing exposed silver salts in the film emulsion into and affects light according to the frequency or color of metallic silver. The reduced silver and the film base the light source. This effect is sometimes called “spectral are completely neutral in color and therefore present density” because the density presented is directly related only “neutral density” to the light passing through it. to the spectral characteristics (frequencykolor) of the The negative presents the same density to all colors or light source. frequencies of light. To illustrate this concept, each step The total density is the sum of the neutral density of a standard 4 x 5 Stouffer step tablet was read with of the reduced silver in the emulsion plus the spectral an X-Rite model 820TR color densitometer, yielding density resulting from the effect of the stain on the color density readings for the red, green, and blue channels. of the light passing through the negative. Readings were also taken with a Speed Master TOTAL DENSITY = SILVER DENSITY SPECTRAL Universal black and white densitometer, which was + DENSITY OF STAIN calibrated with the same calibration reference standard traceable to the National Bureau of Standards. The This is an important concept and the foundation of density values of each step are in the table at the top the effects of pyro stain in platinum printing. of the chart in Figure D.l, and the values are plotted in the corresponding graph. The Stouffer step tablet is an ideal tool for this 0BS E RVATI ON s experiment. It contains 21 steps, each 1/2 stop apart, or indicating 0.15 difference in silver density. One stop The amount of stain in a pyro negative is proportional or Zone of density equals 0.3, 1.5 stops equals 0.45 of to the silver density. This means highlights take on more density, 2 stops equals 0.6, and so on. The base is stain than shadows, and this can be seen by looking completely clear with a zero value for film base plus fog at the step tablet densities in Figure D.5. The W density (FB + F). of step 18 is 0.26, which is about where I would Stouffer Step Wedge TP4x5 RGB and B&W Densities (B+f= zero) 3.50

3.00

2.50

-3 2.00 v) 5 a 1.50

1.oo

0.50

0.00 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 Tablet Step

FIGURE D. 1 STOUffER STEP TAblET DENSITIESAS MEAsuREd ON A SpEEd MAS~FRUNIVERSAL BIM k ANd WklTF DENSITOMETERANd 4~ X-RITE 820TR COLOR DENSITOMLTERACIUA~ bA[UES fOR FACk STEP ARE t0NIAlNEd IN rkt TAblE AT TkE Top 01 TkE CkART All COLORS Of 11qkT ARE blockEd rgiiALly 176 9 APPENDIXD

D-76 RGB and B&W Densities (fb+f subtracted) 3.00

2.50

2.00 E 1.50 0

1 .oo

0.50

0.00 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 Tablet Step

normally place my shadows. The black and white of light, the others will be the same. The density density is 0.16, so the stain is adding 0.10 in spectral presented by silver in the emulsion is frequency or color density, or 1/3 stop. The UV density of step 1 is 1.89, independent, a truly neutral density. which is about where I would normally place my brightest highlights. The black and white density is 1.32, so the stain is adding 0.57 in spectral density-almost 2 ADVANTAGESOF PYRO:“STAIN Is YOURFRIEND” full stops! Figure D.6 shows both the silver density and spectral density of each step. Perhaps this helps clarify A major benefit of pyro is being able to obtain a good why a heavy stain is not necessarily preferred or even platinum print and a good silver print from the same beneficial in platinum printing. Printing exposure times negative. This is very difficult when traditional negative can become exceedingly long because of the extra developers are used because the platinum negative must spectral density that comes along with a heavy stain. be ‘‘overdeveloped’’ relative to the silver negative with At first glance, I found it curious that the black the same developer to obtain the necessary density range and white readings generally matched those of the red (DR) for a platinum print. This characteristic of pyro channel on the 820TR. Many photographic materials comes in very handy when you need to provide glossy have little or no sensitivity to red light, but a look at the silver prints for exhibition announcements, press density graphs for the Stouffer step tablet and the D-76 releases, and for other promotional purposes, or if you negative explains why this does not matter. Negatives just want to work in both mediums. You do not have to developed in traditional nonstaining developers have develop two negatives differently for silver and platinum virtually equal density values for red, green, blue, and printing. Plates D.2 and D.3 illustrate this characteristic black and white channels. So if you measure one color of pyro. PYRO UV, RGB, and B&W Densities (fb+f subtracted) 2.00

1.80

1.60

1.40

1.20 2cn 5 1.00 0 0.80

0.60

0.40

0.20

0.00 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 Tablet Step

FIGURE D.5 PyRO NECiATIbjE STEP DENSITIES A5 MEASUREd ON A SpEEd MASTERUNiVERSAl BlAck 4~dWkiTE DENSITOMETER, AN X-RITE 820TR COlUR DENSITOMETER, ANd AN X-RiTE 36 1 T uv DENSITOMETER. ACTUALVALUES fOR EACk 5TEp ARE CONTAlNEd IN TkE TAblE AT TkE TOP Of TkE CkART

Pyro provides very fine separation of highlights While pyro can be a valuable tool for the platinum because you are not pushing the silver density to the printing, it can get out of control very quickly. Heavy edge of the shoulder of the film curve. Plate D.4 is an stain can result in exceedingly long print exposure times image that demonstrates the ability of pyro to produce of 30 minutes to an hour. Because of the greater effect finely separated highlights. Silver densities of highlights of the stain on ultraviolet light than visible light, a very in a pyro negative are relatively low compared to small amount of stain yields a large amount of spectral negatives processed in traditional developers. density. Consequently, the subject brightness range (SBR) is Another major disadvantage of pyro is that the distributed evenly along the straight-line portion of the staining action does not lend itself well to using rotary film curve and rarely reaches the shoulder of the curve. processors or dip-and-dunk tanks for development. Many people are uncomfortable with tray development, which is the best method for processing negatives in pyro. DISADVANTAGESOF PYRO: “STAIN Any densitometer is a luxury to most photogra- Is YOURENEMY” phers. Pyro negatives require a special UV densitometer such as the 361T. They are very expensive when Pyro stains the film base slightly, and it is enough to purchased new, and used units will become scarce due add 1/2 a stop (0.15) to the FB+F baseline density of the to their declining use in the graphic arts and printing negative. This means platinum printing exposure times industries. will be at least 50% longer for a pyro negative. This Pyro is a very toxic chemical. You must avoid effect becomes even more pronounced when using low breathing the powder and any skin contact with the intensity UV light sources. solution. Wear an appropriate approved dust mask and 178 APPENDIXD

Silver Density and Total Density of Pyro Negative (fb+f subtracted)

Tablet Step

use ventilation when working with the powder. Latex or equivalent gloves are absolutely required when tray processing, and the darkroom must have good ventila- tion. With good darkroom and chemical handling practices, pyro is no more dangerous than other common developing agents or chemicals such as metol or ferricyanides. Pyro stains clothing badly and permanently. Chlorine bleach barely touches it, so wear old clothes. A friend had to stop using pyro because it was staining the tops of the washing machines in the laundry area where he did his film processing. FIGURE 0.7 X-RITE Modtl 7617 (Itfr) ANd ModEl 820TR (RiqhT) DENSIlOMETtRS Ustd foR REAdlNq All NEGATIVES DENSITOMETERSFOR READING PYRO NEGATIVES

Traditional black and white and color densitometers are It is a fallacy that you can use a blue filter with useless for reading pyro negatives for platinum printing a black and white densitometer to try to approximate because they cannot detect the spectral density added the response to UV light. While a filter can be designed by the stain for UV light. The light source and the light to pass the same frequency of UV light used in platinum sensor of these densitometers do not emit or measure printing, the light sensor of the densitometer must UV light. They are designed for use with visible light also be sensitive to UV light and therefore be able to for traditional black and white silver materials. read density at that frequency. As noted previously, black and white densitometers tend to read light in the processes use UV-sensitive materials. The 361T has two red range-the opposite end of the spectrum from W color channels: “ortho” and W. The ortho channel is range-so putting the right filter in the light path doesn’t essentially reading green light. A comparison of density make the sensor able to read UV light. It is “blind” to values between the ortho channel of the 361T and the W light. green channel of the 820TR showed all values within Color densitometers such as the model 820TR 0.02-statistically identical. Therefore, direct correla- are also of little value for reading pyro negatives for tions can be drawn between the data from the two units, platinum printing. While the blue channel readings do as I have done in the graphs in Figure D.5. The UV show the increased spectral density added by the stain, channel reads light in the 350 to 420 nm UV range, there is a significant difference between blue channel the same frequency of light to which platinum materials and W density values-1/2 stop in the mid-tones and are sensitive. The most common BL fluorescent tubes a full stop in the highlights. used for platinum printing light sources emit W at a Since the platinum process uses UV light, a peak of 350 nm, so the 361T is ideal for use in platinum densitometer must be able to emit and read W light printing. to be of any value in reading pyro negatives for platinum The X-Rite model 36 1T densitometer has been printing. The X-Rite model 361T was designed for the standard equipment in the graphic arts industry for graphic arts and printing industries where many of the decades. (Source: XR) There may be other models 180 APPENDIX D

by other manufacturers that are designed for the same densitometers. For a flat fee, they will completely purpose. I am just simply not aware of them. The refurbish the unit, repairing or replacing everything emergence of digital technology in the industry is that is required to return the unit to like-new operating causing many graphic arts houses to sell off this condition. equipment because it is no longer needed for many applications. Model 361T units still show up on online auctions and sell for between $200 and $500. They FILM RESPONSETO PYRO are also still available new from X-Rite for $2750 if you have the extra change to spend. A couple of Some films stain more heavily than others, but the cautions are necessary when buying these units in amount of stain is directly related to the processing Internet auctions. The unit should display “TST PASS” technique and the amount of oxidation of the developer. in the LCD display when powered up. These units can Table D.l lists the films I use, the effective film speed be anywhere from a few years to 20 years old, so you (EFS), and FB+F stain densities with Wimberley WD2D may also want to ask the age of the unit. The lamps Pyro Formula at “N” development for three films. do wear out and have to be replaced. If the lamp has I find it interesting that TMAX 400 showed a been replaced, there is an alignment procedure that significant difference in UV FB+F between the 4 x 5 must be performed for the unit to work properly. negatives used for the tests and actual 8 x 10 in-camera A calibration tablet is a “must have,” and if one does negatives. I suspect that the processing of 4 x 5 nega- not come with the unit, it can be purchased on X-Rite’s tives results in heavier stain because more sheets are Web site (www.xrite.com). The X-Rite Company also being developed at a time, resulting in more turbulence offers refurbishment service for all models of their of the developer and, therefore, more oxidation of the Film E FS UV FB+F Ortho FB+F

Bergger BFP200 (12 x 20) 100 0.20 0.10 Ilford HPS (12 x 20) 200 0.26 0.13 Kodak TMAX 400 (4 x 5) 200 0.36 0.14 Kodak TMAX 400 (8 x 10) 200 0.20 0.08 developer. The key observation from this data is that effects are a perfect combination for platinum. Tri-X the stain adds about 1/2 a stop of additional FB+F, yields similar results as TMAX, but the reciprocity resulting in at least 50% longer exposure times in characteristics requiring ever increasing exposure in low platinum printing. light situations make long exposures difficult to manage. For 12 x 20 images, I use Ilford HP5 and Bergger Many of the exposures inside the cathedrals required BFP200, the only two commonly available films in this 10 to 30 minutes on TMAX 400, which would have format at this time. I rate HP5 at 200 and BFP200 at been at least an hour or two with Tri-X. Also, edge 100. I use TMAX 400 exclusively for 4 x 5 and 8 x 10 effects do not seem nearly as pronounced with Tri-X formats. Its pronounced contrast and beautiful edge as with TMAX. I rate TMAX 400 at 200 and reduce 182 APPENDIX D

development to maintain good, fat shadow detail, yet potassium bromide in Solution B as a substitution for printable highlights. Kodak Anti-Fog (benzotriazole), which was in the A particularly interesting aspect of the Bergger film original WD2D formula. I had difficulty obtaining is that is seems to require longer development times and sufficient contrast in the resulting negatives, and higher concentrations of developer than other films. development times were exceedingly long. I eliminated I do not know if this is also true of the Bergger film with the bromide, which solved both problems, and traditional film developers.’ It may not be a character- I have not noticed any fogging problems after several istic of the film at all, but rather a result of using lower thousand 4 x 5, 8 x 10, and 12 x 20 negatives on contrast, single coated process lenses on the 12 x 20 a variety of films. Be aware that the WD2D formula camera. I have not used any of those lenses with TMAX has been formulated both with and without the Kodak film in the 8 x 10 camera, so I have no common Anti-Fog or benzotriazole. The formula published reference from which to draw any conclusions. in Petersen’s Photographic in 1978 included Kodak Anti-Fog. The first edition of The Book of Pyro (Hutchings, 1991) included benzotriazole in the for- PYROFORMULAS mula, but later editions did not. The formula that I use is as follows: There are a variety of pyro formulas dating back well over 100 years. The ABC formula was extremely John Wimberley’s WDZD Pyro-Metol Formula Solution A popular for many decades in the early and mid- Distilled Water (at 125 F) 1 liter twentieth century and was used by Edward Weston. Met01 3g It was the first pyro formula I tested. The ABC formula Sodium Bisulfite 10 g does not contain any metol. Pyro is the sole developing Pyrogallol 30 g agent and because of this, shadow density is reduced significantly. This has the effect of a loss of about 1/2 Solution B Distilled Water 1 liter to 1 full stop in film speed. More recent formulas such Sodium Carbonate as John Wimberley’s WD2D and Gordon Hutchings’ (monohydrate) 40 g PMK include metol to enhance shadow detail and avoid the loss in film speed that is characteristic of the John has since reformulated WD2D as “WD2D+” and ABC formula. The Rollo-Pyro formula was recently is selling it through a retail photography chemical introduced and is designed specifically for use in rotary supplier. The new WD2D+ formula is proprietary processors and is essentially an adaptation of PMK. and is not the same as the original WD2D formula. The color of pyro stain varies with the developer Adjustments in development will be necessary with formula. Formulas that use sodium carbonate as the this version of the formula. alkali-Wimberley and ABC-produce a stain that is yellowish-brown. The PMK and Rollo-Pyro formulas OTHERPYRO FORMULAS use sodium metaborate as the alkali and produce a pronounced green stain. It is primarily the yellow Other pyro formulas can be found in The Book of portion of the stain that has the greatest effect on UV Pyro by Gordon Hutchings (1991) or Ansel Adams’ light. The blue component of the PMK green stain will The Negative (1981). pass most UV light, but the yellow portion of the green stain will block W light. The pyro-metol formula that I use for all film PYROPROCESSING INFORMATION AND TIPS processing is identical to John Wimberley’s original WD2D formula, except for removal of the restraining The most important factor in obtaining consistent agent in solution B. Originally, I included 1.1 g of negatives and prints is a consistent processing regimen and timing of each step of the process. Pyro quickly begins to oxidize as soon as the developer and alkali are mixed (parts A and B). The longer the developer is Editor’s Note: Testing Bergger film BFP200 using the Plotter exposed to air, the darker it becomes, and the deeper the Program” I have found the film to be basically unresponsive to changes in development with D76 developer. (See Appendix C: Some resulting stain. Pyro that has been sitting in an exposed FildDeveloper Combinations to Produce a Platinum/Palladium tray for 30 minutes before use will yield a very deep Negative.) D.A. stain and will also result in a much darker silver image from increased developer activity. The resulting nega- of the developer flowing through the holes on the tives are what would be described as “bulletproof,” both hanger edges causes extra staining and uneven devel- because of the higher silver density but mostly because opment. Other methods, such as rotary processors, the deep stain presents a very high spectral density to the also have their share of problems. They tend to overly UV light used in platinum printing. oxidize the developer because air is constantly being The developing action of pyro and the associated inserted into the solution by the equipment action. stain effects are very sensitive to small variations in Greater oxidation of the developer results in deeper developer temperature. Pyro oxidizes more rapidly as stain and more reducing action of the developer. Many the temperature of the solution increases. If you tray people also report streaking from the rotary action. develop, use a water bath around the trays. Without The best methods for pyro development are tray a water bath, a 68” F solution will easily climb to 70 or development and nitrogen burst. Few people have 72“ during development just from heat transfer from nitrogen burst equipment, which means tray develop- your fingers. If the air temperature in the room is higher ment is the best option. Roll film can be developed in than the developing temperature, the solution tempera- tanks, but the agitation method must include both tures will gradually rise as well without a water bath. inversion and rotation. Pure rotational agitation will A two-degree increase in developing temperature can cause extra turbulence along the reel edges and result have a significant effect on total negative density for in uneven development and stain along the film edges. a pyro negative. The accelerated action of pyro on Difficulty in maintaining processing consistency has both silver density and increased stain is additive in the been one of the major criticisms of pyro over the resulting negative and therefore has an almost doubling decades. These are reasons why many people, including effect, as if the negative had actually been developed Ansel Adams, felt that pyro was just too difficult to even longer. work with or control. The increase in stain has the greatest impact for Negatives are developed in trays-eight to twelve platinum printing. Pyro does not oxidize as quickly in 4 x 5 sheets, six to eight 8 x 10 sheets, or four to five a full closed tank because there is a limited amount 12 x 20 sheets at a time. The number of sheets is based of oxygen in the tank. The staining effects are less on how many I can comfortably shuffle through in pronounced for the same development time, which a 30 to 45 second cycle without scratching negatives. must be taken into account when developing roll film Agitation is constant in that I am constantly moving intended for platinum printing in pyro. the bottom sheet to the top of the pile-throughout the My formula and processing practices do not follow development process without pause. The negatives are the philosophy of maximum stain/minimum silver. presoaked in water for 3 minutes and then transferred It is worth repeating again that in platinum printing, to the pyro. stain is your friend and stain is your enemy. Only a My standard developer dilution for TMAX 4 x 5 very small amount of stain goes a very long way in and 8 x 10 films is 1:1:15 for solution A, solution B, and terms of the amount of density it presents to UV light. water, respectively. I use a 1:1.1:10 dilution for Bergger A heavy stain only increases the print exposure time, and HP.5 12 x 20 films. These dilutions work well for so practices such as “post-staining” should never be normal and both “minus” and “plus” development of employed on negatives for platinum printing. The negatives. For normal negatives, I develop TMAX 400 post-stain bath only increases the overall stain of the at 68” F for 15.5 minutes, plus 30 seconds to displace negative and therefore baseffog density, by as much the water from the presoak. BFP200 and HP5 are as 0.30 to 0.45 in density. That equates to a full stop developed for the same time but at 70” F. I have not or 1.5 stops in printing time-a 7-minute exposure conducted extensive tests, but I suspect the differences becomes 14 to 21 minutes. Since development of the in developer concentration and temperature for the image has been stopped and unexposed silver fixed Bergger and HP5 films is actually compensation for the out, a post-stain step does not add stain in proportion lenses I use on the 12 x 20 camera and not indicative to the silver density. It only moves the existing tones of any difference in those films. Most of my lenses are up the curve. Consequently, printing times can easily Artar designs with air spaced elements and therefore be doubled or tripled by a heavy post-stain step, with are lower-contrast lenses. The higher developer tem- no real improvement in tonal separation. perature and concentrations are likely just compensating Traditional development methods, such as dip- for the lower-contrast lenses. and-dunk tanks with stainless steel hangers, do not The negatives are developed emulsion side up, work with pyro. The turbulence and eddying currents and halfway through the development time I rotate the 184 APPENDIXD stack 180 degrees to even out development. Otherwise, the reactivity of the developing agent, and therefore the end of the negatives that are lifted to remove the the oxidation of the pyro. The oxidation causes the bottom negative from the stack tend to get slightly less developer solution to turn dark, which is what stains development since they are repeatedly lifted above the the reduced silver of the image. Increasing the amount surface of the solution, even if only for a brief moment. or concentration of part B increases developer activity, I have tried emulsion side down development but had and decreasing either one does the opposite. Once too many scratches in the negatives, which I cannot you understand how part B affects the developer, you completely explain. can use this knowledge to make fine controls in the A tray of distilled water is used instead of an development process. acid fixing bath. Any developing action that continues A second form of development manipulation and before the negatives are immersed in the fixer will control available with pyro and not traditional devel- only enhance the shadow detail with very little effect opers is intentionally allowing the developer solution on the highlights. I started this practice when I was to oxidize for 5 to 15 minutes in the tray, after being having some problems with my development process mixed but before developing negatives. This form of and was trying to eliminate variables. I saw no signifi- control should only be attempted after considerable cant differences between an acid stop and a water stop experience with a particular formula and a thorough bath, so I stayed with the water. It is cheaper since working knowledge of the other processing controls the stop bath must be discarded after each process used with pyro. Using a highly oxidized developer cycle because of the oxidized pyro carryover from the will result in a much heavier stain in the negative, and developer tray-plus the acetic acid odor is eliminated. therefore very long printing times for platinum. A highly Contrary to most of the experts’ recommendations, oxidized pyro developer is also more active in terms of for over 15 years I used a prepackaged hardening fixer, silver reduction, so it is very easy to overdevelop the Kodak Fixer, for my pyro negatives. It undoubtedly negative to the point of being “bulletproof.” Repeat the removed some of the stain, as does the hypo clearing mantra: Stain is your friend and stain is your enemy. agent, but I have never had a problem with too little Because pyro developer oxidizes unevenly in the stain. A very small amount of stain goes a long way tray, it is important to maintain regular agitation. in platinum printing. I have since changed to using the Longer development times are recommended to help non-hardening F-24 fixer formula, but purely to elimi- ensure even development, especially in tray develop- nate the strong and irritating odor from the boric acid ment. Development time should never be less than in Kodak Fixer. Even with good ventilation in the 7 minutes. I adjusted my developer concentrations darkroom, the boric acid odor is irritating to the nose and temperatures to keep N development around 15 and lungs in even tiny doses. I have not noticed any minutes, which keeps “minus” development no lower difference in the amount of stain on negatives after than 13 minutes. changing fixer formula. I do not recommend the use of ammonium-based “rapid” fixers with pyro. I believe they slightly bleach the highlights in the shadows of CONCLUSION negatives, although I have not run controlled tests. Film is fixed for 10 minutes and then run through Pyro has seen resurgence in recent years. Using hypo clearing agent, washed for 20 minutes, soaked in pyro requires good control of the development process Photo Flo“, and hung to dry. and consistency in processing practices. Experience is necessary to fully understand the behavior of pyro and resulting stain in the development process and the role ALTERNATIVEPROCESSING CONTROLS WITH PYRO that the stain plays in platinum printing. While pyro is an old and dependable developing agent, lack of When using traditional developers on film, most attention to consistency in developing practices can development manipulations (e.g., N-1, N+1, etc.) are have dramatic effects on the resulting negatives. done through adjustments to the developing time or Excellent platinudpalladium (PtPd) prints can be developer concentration. With two-part pyro devel- made from negatives developed in any developer, given opers, further control is possible by increasing or that proper care is taken in learning the materials decreasing the amount of the alkali in part B or the and controlling the exposure and development process. amount of part B in the working solution. It is the alkali Pyro can provide benefits for the platinum printer (sodium carbonate/sodium metaborate) that accelerates regardless of the formula used. APPENDIX E CRAFTINGDIGITAL NEGATIVES FOR CONTACTPRINTING PLATINUMAND PALLADIUM Mark I. Nelsoii

185 186 APPENDIX€

When Dick Arentz asked me to write this appendix, Smooth Gradient Test Tablet: A tablet with levels I thought for some time about what would be the most 0 through 255 created by using the gradient feature important contribution I could make. I decided that of Photoshop".' rather than give very specific "how to" instructions, Color Density Range Control (patent pending): The which is a whole book in itself, I would present use of varying colors in digital negatives to match important concepts by covering the following: the density of the negative to contrast range Digital image file capture and preparation that requirement of the alternative process. will produce better negatives Standard Color Density: The color or hue that An understanding of how digital negatives really prints with just enough density to produce paper work and why they often fail white with a given Pt/Pd contrast mix when printed Methods of achieving precise control of the print with the Standard Exposure Time. with a digital negative Color Density Range Palette: A file created in A standard workflow for making platinud Photoshop'p that generates a step tablet with steps of palladium (Pt/Pd) prints using digital changing color in graduated increments that is used negatives rendered with imagesetters and inkjet to determine the Standard Color Density. printers-the two most commonly used digital Tonal Palette: A digital step tablet made using the negatives Standard Color Density that has enough steps to be If you are currently printing platinudpalladium used to determine the Process Adjustment Curve for with digital negatives, or are considering doing so, you a given contrast mixture. Once printed in Pt/Pd with should find this information extremely helpful. I think the Process Adjustment Curve applied, the Tonal I can safely say that the methods I have developed will Palette provides a visual tonal index that can be give you more control than ever before possible, thus used for planning and predicting the tonal values allowing you to make a print that is superior to what of a print. has been standard practice until now. These skills give Process Adjustment Curve: A curve adjustment that you freedom to create and print images that match your is derived from measuring the printed steps of the vision. Tonal Palette. The Process Adjustment Curve adjusts the ink densities of all the 256 tones in a digital negative relative to each other such that the tones print in a linear fashion with Pt/Pd. GLOSSARYOF TERMS Of the information presented, there are two basic con- Standard 21 -Step Test Tablet or Step Wedge: cepts that I consider the most important to understand: A commercially available transmissive step tablet with 21 steps of increasing density 1. The Density Range of digital negatives produced in increments of log .15, which is with color output devices can be precisely controlled equivalent to 1/2 stop exposure. When contact prior to the application of the Process Adjustment printed next to digital negatives and targets, Curve. This is a key factor in taking control of the this provides a check for consistency of process. Subsequently, the curve required to adjust contrast mix, exposure, and other printing the relative tonal values is far less drastic and less variables. destructive to the tonal information in the image file. Previously the Process Adjustment Curve alone Digital 21-Step Test Tablet: A file created has been used to account for the density range in PhotoshopE' with equally spaced steps 21 adjustments of digital negatives. Figure E.l shows of tones with an increment of 12.8 from the relationship between the Exposure Scale of an (black) to 255 (white). This test tablet is 0 Alternative Process and the Density Ranges of three used for visual evaluation of the negative's negatives. In one case (shown in Green), the relative printed densities. The steps will have negative with the higher Density Range will result different density values than a Standard in an exaggerated Process Adjustment Curve, which 21-Step Test Tablet and will only print in will reduce the number of tones in the negative. a linear fashion if the correct Process Adjustment Curve has been applied to the digital '. Precisiotz Digital Negatiiies for Sihler arid Other Altertiative file. Photographic Processes by Mark I. Nelson (2004). In this case, the Process Adjustment Curve must compensate for the gap between the end of the Exposure Scale and the extreme Density Range of the negative. The second mismatched example (shown in Blue) is a negative with too low a Density Range. This negative will clip the Toe of the Exposure Scale and print the highlights darker than desired. The third example (shown in Orange) is an exact match of the negative’s Density Range with the Alternative Process’s Exposure Scale. This exact match will minimize the Process Adjustment Curve, preserve more tones in the negative, and print the entire tonal range of the negative. 2. The primary variables you can manipulate when printing platinum and palladium with digital negatives are the Contrast of the mix, the Density Range of the negative, the Standard Exposure Time, continues to grow stronger and reach deeper as the and the Process Adjustment Curve. Once you photographer continues the journey with this image to understand the relationship between these four the final pi nt. variables shown in Figure E.2, you can explore creative manipulation of these variables to create THE DIGIAL VERSUSINXAMERA prints that match your vision for your images. NEGATIVECONTROVERSY While technical skill may lead to a “perfect print,” the exercise is futile if there is no content in the image. There are topics in every field of endeavor that are likely Ultimately, what matters most is the final image and the to bring on a heated debate. Imagine the “discussions” impact it has on the viewer. All the expensive equipment that took place between the first photographers and and all the technical knowledge and skill in the world the painters of that time. The rapid development of does not a great print make. I think the most important digital imaging and digital photography has led to ingredient is that which comes from deep inside the another such debate. This chapter is not intended to. fuel artist-an artist who is willing to risk looking within as this debate nor be the final word. he or she studies the subject and forms a connection I do not see either traditional in-camera negatives with it prior to taking the photograph. This connection or digital negatives as preferable or one as being 188 APPENDIX€ superior to the other. I see them both as tools to be used Scanner or reflective densitometer for determining in slightly different workflows to achieve the same end- Process Adjustment Curve a beautiful image rendered on fine paper by a photo- PhotoshopR or other image editing software and graphic process that is capable of making that image a working knowledge of image preparation sing to the viewer. Excelrh'or other spreadsheet software I do not hope that everyone will start making digital Light table (optional) negatives to craft their platinudpalladium prints. Loupe (a 3x and a 1Ox are nice to evaluate I do hope that many people will continue to improve at different magnifications) and use in-camera negatives to make fine prints. The Hygrometer for monitoring humidity photographic community benefits from having this A working knowledge of PdPd printing, including variety. Each method has its own benefits and pitfalls. methods of contrast control To truly master each is equally challenging. Experi- Stouffer or Kodak Standard 21-Step Tablet mentation with each method adds to the knowledge (the most important item on this list-and the base for alternative photographic processes. cheapest) I was fortunate to begin my photographic journey And, if you are making inkjet negatives: at a time when so many options were opening up. I was introduced to computer graphics through my Inkjet printer professional work. Since I had settled on the 35 mm Film substrate for printing negatives format years ago, it was only natural that I turned to enlarging negatives digitally. My first efforts were with imagesetter negatives. Soon I heard about the SOME DIGITALBASICS pioneering work being done by Dan Burkholder and In order to understand the content in this appendix, it is David Fokos. important to be familiar with a few terms that are used For over a year prior to writing Precision Digital in digital imaging. Negatives for Silver and Other Alternative Photographic Processes and subsequently this chapter, I spent the majority of my time researching digital negatives. My PIXELSVERSUS DOTS desire for a better understanding of how they work led to experimenting with ways to improve them. I did so One important aspect of digital imaging that confuses because I wanted the technical ability to make the best many beginners is the relationship between image size, possible prints using digital negatives. I was not file resolution, and the resolution of inkjet printers and convinced when I started my research that it was even other output devices-the difference between pixels and possible to make a great print using a digital negative. If dots. I found it couldn't be done, I was resigned to using Image files are defined by pixels, or points of traditional methods for my enlarged negatives. different tones and hues. The resolution of capture Fortunately, I think I was successful. Each day I feel I devices, such as cameras and scanners, or the resolution am learning more about these wonderful processes, such of monitors are all defined by how many pixels per inch as platinudpalladium, which in turn leads me to new (PPI) or millimeter they resolve. methods for improving my workflow. Output device resolution is determined by how I would like to thank Dick Arentz, Phil Davis, many dots they can print in an inch (DPI) or millimeter. Sam Wang, Sandy King, and Bruce Starrenburg for their Dots are not the same as pixels. Output devices such help in writing this appendix. as imagesetters and inkjet printers need to print a pattern or matrix of more than one dot to render each pixel in an image file with the appropriate tone MATERIALSAND EQUIPMENTLIST and/or color. There is usually a ratio for each device of how many dots are needed to accurately represent You will find an excellent list of materials required pixels. for platinum/palladium printing in the main body of this Imagesetters come in different native resolutions book. Specific materials required for making digital of 2400, 3600, and 4800f dots per inch. Imagesetters negatives are as follows: require a 16 x 16 matrix of dots to represent the Computer 256 possible tones in a pixel. Thus, you can calculate Digital image file the maximum number of pixels per inch the imagesetter can render and still give 256 tones by dividing the native resolution by 16 (e.g., 3600 dpi/l6 dots = 225 pixels per inch maximum resolution with 256 tones). The exceptions to the pixel/dot ratio requirement are the high end imaging devices such as Lightjet'", Lambda"', and ChromiraT" that use lasers or LEDs to image on paper and film. These devices can vary the tone and color of each dot printed in a one-to-one relationship to the pixels in the image file. This feature provides output that appears to be continuous tone to the human eye and even holds up well under close examination with a loupe.

DIGITALIMAGE TONES One of the virtues of platinum and palladium printing is the wonderful, extended tones you can achieve with the process. Digital negatives can render beautiful tonality, but, as you will see, they have their limits, and all effort should be made to avoid going beyond those limits. The range of tonal values of the pixels in an image file is limited by the "bit depth" of the file. You have probably heard the terms 8-bit and 16-bit images. Bit depth is determined by the software and/or device used in capture. The bit depth numbers, such as 8,10, 12, 14, or 16, refer to the number of possible tones that the file, software, or device can accommodate. This number is actually applied as the exponent of the number 2. Thus, an %bit image is 2 to the power of 8, or 256 possible tones from black to white. Sixteen-bit images have 2 raised to the power of 16 or 65,536 possible tones-a big difference. Thus, 16-bit images give you much more room to make tonal adjustments to a file. Though some tones will be lost, a large number will survive. When tonal adjustments are applied to %bit files, gaps will appear at some tonal ranges (poster- ization), and other tonal ranges will be compressed (loss of contrast) as shown in the comparison in Figure E.3. Since color or RGB (red/green/blue) files have or how the image was manipulated after capture. three channels, one for each color, they may be referred The best practice is to capture and work with images to as 24-bit, 36-bit, or 48-bit files. For the most part, at the highest possible bit depth to preserve as many this appendix refers to 16-bit grayscale files. The only tones as possible. Every time you make an adjustment exception to that is when printing negatives on a color to an image, the image loses some tones because output device. At that point, it is necessary to convert almost all image adjustment tools are destructive in the file to RGB just for printing. Files that are used nature. for printing negatives on imagesetters should remain in This issue becomes very important when you print grayscale mode. your negative. All current imaging devices render images Notice I used the term possible tones. An image in only 256 tones or %bit images. While you can send may not fill up the entire range of tones for a given a 16-bit image to an inkjet printer, it is converted to 8 bits bit depth, depending on how the image was captured or 256 tones during the printing process. 190 APPENDIX€

THE DIGITALIMAGE FILE Cameras and scanner software usually both have The digital image file may originate from film that a sharpening feature. Turn it off and do your is scanned or a digital camera. The process prior to sharpening later in Photoshop’-you will get converting the image to a negative and making a print better results. If your digital camera has a contrast can be divided into two phases: the Capture Phase and setting, set it to the lowest value to keep tonality the Image File Preparation Phase. smoother. Contrast adjustments should be made later in Photoshop”. If you are faced with photographing a scene with DIGITALIMAGE FILE CAPTURE an extreme subject brightness range that is The following suggestions cover just a few of the more beyond the capability of your digital camera, you important issues related to capturing a digital image may be able to capture the scene by making three with a scanner or digital camera. There are whole books exposures-one exposed for the highlights, one written on these topics. In them you will find more exposed for the shadows, and one exposed in in-depth coverage than possible in this chapter. One between. Use a tripod. Later, in Photoshop ‘, you of my favorites is Real World Adobe Photoshop CS, can combine the three into one image that renders by Bruce Fraser and David Blatner (Peachpit Press, the full tonal values of the scene. Similarly, if 2004). you are having difficulty scanning a negative that has a high density range, you can make Regardless of whether you are using a scanner bracketed scans to combine into one image in with film or a digital camera, work in 16-bit PhotoshopR. mode if possible. If you are using a digital camera, and it has RAW file capability, use that format at the highest resolution. Avoid JPEG file format or DIGITALIMAGE FILE PREPARATION any file format that uses compression techniques. This creates artifacts in the image that will show This is where you further prepare the digital image up in the print. Use “lossless” file formats such to match your visualization of the subject when you captured it with your camera. While there are some as Photoshop’”, PSD, or TIFF. important printing techniques that will be covered later If you are using a digital camera that does not have a 16-bit mode, expose your images in color to fine tune this, you are now at the point where you will in TIFF format. Import the file into PhotoshopR do most of the adjustments that make the image look the way you want it to print. It is very important that your and immediately convert it to a 16-bit RGB file. computer monitor be calibrated so that the image file Then use the channel mixer to convert the file to is rendered accurately on the screen. If the monitor is not grayscale mode. This will give you a much richer calibrated, you will not be able to make prints that look grayscale file, since information from all the color like what you see on the screen. channels is being used for the conversion. When scanning or using the digital camera, be Open your image file and only apply enough very careful of your settings. A common mistake sharpening to recover any softness in resolution is clipping the highlights or shadows of an image, resulting from scanning or the digital camera. which will lead to blown out highlights or Do this while observing the image at 100% blocked up shadows in the print. This process is resolution on the monitor. Do not oversharpen referred to as setting the Black Point and White here. You are not sharpening at this point for Point in the Levels Adjustment. The image printing. Sharpening, as you will learn later, is histogram will show if this has happened, since best done in three steps, each for a different there will be a spike of data on either the black purpose. The other advantage of doing this value (0) or white value (255). “recovery” sharpening is that it will make it easier Most scanner manufacturers use inflated values to see unwanted artifacts when you clean the file. for the “Dmax” capability of their products. Be Now it is time to clean up the image. Like a crime sure you know what the actual capability of your scene detective “walking the grid,” go over the scanner is. If you are exposing film with a greater entire image at 100% resolution and touch up density than your scanner is capable of managing, any dust spots, film scratches, or other problems then either get a better scanner or modify the stemming from the file capture. Use primarily the density range of your negatives. Clone Tool or, my favorite, the Healing Brush to do this. Sample from a nearby area having a snapshot of that change, undo the global similar texture and tone before clicking on the change to the image or revert to the previous offending spot with the tool. Avoid using the state, then by targeting the snapshot you Global tools, such as Dust and Scratches, to just made as the source for the History Brush, accomplish this task. If you have a really serious paint into the image the changes just for the problem, you might be able to use the Dust and local area you want to affect. You can even Scratches tool locally in combination with the adjust the percentage of change you want to make History Brush to clean up a problematic area of and by brushing over the area a number of times the image. Applying a tool like this to the entire add the change in small increments. A powerful image may get rid of a lot of tiresome dust spots, tool! but it is also going to get rid of important detail in The first local adjustments made will probably the image. Just imagine what a tool like this is be tonal adjustments, as one would burn and going to do to all the detail around the eyes in dodge a print in a traditional darkroom. a portrait! Using the eyedropper to sample areas, you Once the file is cleaned to your satisfaction, save can determine what tones you will need to it then use Save As with a new file name. This new adjust and use the Curves Adjustment to file is your working file. If something happens to adjust precisely those tones, and then paint it, you still have the original file to go back to, the changes in with the History Brush. This and you will not have to repeat the tedious is a great method for burning and dodging the cleaning process. image. If you need to crop the image, this is a good Local sharpening can be accomplished in time to do it. Some photographers, especially the same manner with the History Brush. when working with sheet film, like to show This allows you to emphasize a portion of the the entire negative, including the borders. image. If you are not doing this, be sure to crop Like sharpening, only in reverse, you can the non-image area out since it will de-emphasize an area of the image or rid it of introduce false data into your histogram unwanted noise by using the Dust and Scratches when you evaluate it. filter in combination with the History Brush. Assuming you are using PhotoshopR CS (version If the image “feels” finished, save it. 8) or later (if you aren’t using it, get it!), you will be able to do much of the adjustments in Layers, Remember I mentioned that sharpening should be which are nondestructive and can be tweaked as done in three stages? So far you have applied a small needed while you work. amount of global sharpening to restore image sharp- Create an adjustment layer for Levels. Set the ness lost in the capture process. You have also applied endpoints (black and white points) where you some local sharpening in areas you wanted to think they should be without clipping any of the emphasize. The final sharpening, using one of the data. more complex sharpening techniques, such as High Create an adjustment layer for Curves. Here Pass Sharpening, should only be applied when you you really want to take your time and tweak print the negative. The reason for waiting is this the image slowly until you are satisfied with sharpening should be applied “temporarily,” only after the tonal relationships of the image. the output size of the image has been determined. This Now sit back and look at the image. How does type of sharpening is size dependent and should be it look? Study it for a while. Slowly you will done carefully so that your image does not have the begin to see things you would like to adjust- unsightly halo affect that makes people point and shout mostly in local areas of the image. This is “Digital!” This method of three-stage sharpening is where you can really begin to make your image covered in depth by Bruce Fraser on his Web site: sing. www.pixe1boy.com. Local changes to an image, or changes that affect If you have worked an image file so much that it only one area of the image rather than the entire begins to lose the rich tonal values you started with, image, are easily accomplished with the History delete it and start over. One sure indication you should Brush tool. This ingenious tool allows you start over is if the image histogram resembles a comb to make any global change to an image, take with broken teeth or a molting porcupine. 1 92 APPENDIX E

IMAGESETTERNEGATIVES

The first digital negatives were rendered with image- setters. Imagesetters are used in the printing industry to produce the film used to burn printing plates. Since many printing companies are shifting to direct computer-to-plate workflows, service bureaus with imagesetters are becoming more difficult to locate.

How IMAGESETTERNEGATIVES WORK FIGURE E.4 BIT MA^ Wivdo\i Imagesetters are unique in the way they reproduce tone in negatives. Unlike most other devices, they produce only two tones, clear film and solid black. The black It is important to discuss your requirements with the is very dense, measuring in the neighborhood of log 4.0 service bureau before you send them your file. It is often transmissive density or higher. The way imagesetters preferable to have the service bureau convert your file achieve the appearance of continuous tone is by spacing to a bitmap. They may have software for bitmap con- very tiny dots close together or further apart. This fools version that is more compatible with their imagesetter. the eye, but in fact, a PtPd print made with an If so, you will give them an 8-bit grayscale file of the imagesetter negative only has two tones in it! One is dimensions for your negative at 300 ppi and they will paper white and the other is the printed dots that are bitmap the image to 1200 dpi or 1800 dpi. in the area of log 1.5 reflective density. This does not mean that you cannot make a very fine print with an imagesetter negative. In fact, this characteristic makes I NKJET NEGATIVES it rather easy to make a print-almost foolproof. Imagesetters can render tone by two methods. The quality of inkjet printers has greatly improved One, the line screen, is an ordered series of variable in the past few years, making them an excellent choice sized and shaped dots. Most people do not use this for rendering high quality digital negatives. Each month screening method because it can appear too mechanical the major manufacturers are announcing new inkjet when viewed with a loupe, however it may provide printers with smaller picoliter dot sizes and improved smoother tones and less artifacts at certain critical tonal capabilities for rendering smooth tones. Once you transitions. The alternative to the line screen is understand how they work, you can control the stochastic screening. This method uses a “random” output to the extent that the negatives print with little pattern of tiny dots to render tone. This fine random or no digital artifacts. pattern of dots simulates film grain. As mentioned previously, imagesetters come in How I NKJET NEGATIVESWORK varying native resolutions. The higher resolution iniage- setters are usually difficult to locate. It is important to Inkjet printers are designed to make very good positive find out what resolution the service bureau’s imagesetter prints, not negatives. Inkjet printers use the CMYK is capable of rendering so that you can size your file model, which employs cyan (C), magenta (M), yellow accordingly. (Y) and black (K) inks to form colors and tones. In order For stochastic screening, the two most commonly to print good shadow detail and a dense black, inkjet used resolutions are a 1200 dpi bitmap or a finer 1800 printers add the black ink to the CMY in the lower dpi bitmap. PhotoshopK can be used to convert an %bit tones. This is great for making good inkjet prints, grayscale file to a bitmap file of one of these resolutions. but it is terrible for making good negatives. The black Go to IMAGE>MODE>BITMAP, and enter 1200 or ink behaves differently than the C, M, or Y inks- 1800 as the output resolution with DIFUSION DITHER it is opaque rather than translucent and has a very high selected, as shown in Figure E.4. If you look at the image ultraviolet (UV) density, in some cases over log 4.0. at loo%, you will easily see the stochastic screening Inkjet negatives and negatives rendered with other effect. Notice that the image is now made up of black color capable digital output devices function in a and white dots, which is exactly what an imagesetter different way than imagesetter negatives. In a way, prints. they are more like traditional film negatives, and you should think of the combination of film substrate and The following setup can be used for printing inkjet ink as a new form of film negative. However, there is negatives and the Tonal Palette. The examples are based a fundamental difference with this type of negative that on an Epson 2200 printer running under Mac 0s 10.3 can be used to great advantage. and assume a color working space of Adobe 1998 using Instead of blocking ultraviolet light with varying Photoshop CS. levels of opacity, inks-both dye based and pigment 1. Make sure the file is in RGB mode (if grayscale, based-are translucent, and they filter light. As stated convert to RGB). previously, this is true of all the inks except black. 2. From the FILE menu, choose Print With Preview. Thus, printing negatives without black ink provides a 3. In the Print Window, set Source Space to much more controllable negative density. Document. The color filtering effect of inks works in a very 4. Set Print Space Profile to Same As Source. predictable and precise manner, allowing this character- istic to be used to control the density range of negatives Window #1 will look like the image in Figure E.5. over a broad range-easily covering the range required 5. Click the Print button. by platinum and palladium. I refer to this means of 6. In the second Print Window that appears, choose controlling negative density as Color Density Range the media setting that works best with your Control (patent pending). Color Density Range Control printer, such as Premium Semigloss Photo Paper, (patent pending) is extremely important in the crafting Premium Luster Photo Paper, or Premium Glossy of digital negatives because it tailors the density range Photo Paper. of the negative exactly to the exposure scale of the 7. Select Advanced Settings. alternative process. The densest part of the negative, 8. Set the printer resolution to the highest available or where it achieves absolute Dmax, can be matched setting, such as 1440 dpi or 2880 dpi. exactly with the contrast mixture such that the 9. Turn off High Speed. combination prints exactly at paper white. In other words, the Dmax of the negative is matched to the end Window #2 will look like the image in Figure E.6. of the toe of the H & D curve of the contrast mixture. 10. Now select Color Management and select No There is a great advantage to using Color Color Controls. Density Range Control (patent pending). The Process Adjustment Curve is used to adjust the relative tonal Window #3 will look like the image in Figure E.7. values of a negative so they will print properly. The 11. Now click the Print button and your negative will Process Adjustment Curve is also used or abused to be printed. adjust for the mismatch in tonal range of the negative and the contrast mixture. Using Color Density Range Control (patent pending) for this latter purpose then leaves only one goal for the Process Adjustment Curve to achieve-adjustment of the relative tonal values of the image. This allows for a much less drastic, simpler curve and more tones in the final print.

PRINTERSETTINGS FOR INKJETNEGATIVES There are a million ways you can configure the printer driver. This method avoids using any profiles and pro- vides a more even distribution of ink. The inkjet printer drivers do require that you pick a media setting. The better media settings for digital negatives are the ones that lay down more ink and are used for glossy or semi- gloss papers. Test these different media settings and pick a media setting that prints smoothly without artifacts. Precision Digital Negatives for Silver and Other Alteriiative Photographic Processes includes target files and methods for selecting the best media settings. 194 APPfNDlXE

CALIBRATIONFOR PLATINUM AND PALLADIUM PRINTINGWITH DIGITALNEGATIVES

Printing with digital negatives is somewhat the reverse of printing with traditional in-camera negatives. With traditional negatives, the density range varies according to subject brightness range, exposure, film, and the developerkombination used. Thus, when print- ing traditional negatives you match the contrast mix and exposure time to fit the negative density range. When using inkjet digital negatives, the negative is matched to the combination of contrast mix and printing time you choose. This match is achieved by selecting an appropriate Color Density for the negative and subsequently a Contrast Adjustment Curve that works best with this combination. When using imagesetter negatives, the contrast mixture and exposure time are matched to the fixed density of the negatives. FIGURE E.6 PRINTERDRIVER WIN~OU #2 A summary of the workflow for calibration is as follows: 1. Choose a contrast mix. 2. Determine a standard printing time for the film substrate. 3. For inkjet negatives, determine an appropriate Standard Color Density. For imagesetter negatives skip #3 and go to #4. 4. For inkjet negatives, print the Tonal Palette on the film substrate. For imagesetter negatives, send the file to the service bureau for printing. 5. Print the negative of the Tonal Palette with Pt/Pd. 6. Determine the Process Adjustment Curve from the Pt/Pd Tonal Palette. 7. Apply the Process Adjustment Curve to the Tonal Palette file. 8. For inkjet negatives, print a new negative of the Tonal Palette with the Process Adjustment Curve applied. For imagesetter negatives, send the file to the service bureau. 9. Print the Tonal Palette negative with the Process FIGURE E.7 PRINTERDRIVER WIN~OW #3 Adjustment Curve applied with Pt/Pd. You may only need to do this process once. The resulting calibration values you determine can be It is important to note that although inkjet nega- used each time you print a new image-with the same tives may feel dry to the touch when they emerge from results. The Tonal Palette, described more fully on page the printer, they must have at least a couple hours to 196, is a fancy digital step tablet that you create in fully dry or cure after they are printed. Densities can PhotoshopR with from 65 to 101 steps of tones of vary drastically during this time, so be patient and equal separation. The first printing is used to deter- plan ahead. I often print my negatives the day before mine the Process Adjustment Curve. The second I make my Pt/Pd prints. The same holds true for printing printing, with the Process Adjustment Curve applied, the Tonal Palettes during the calibration process. provides you with a Tonal Palette to refer to during the image file preparation phase and when making your negative (about log .05) is usually the same as that of the prints. standardized 21-step test tablet. This can be confirmed by checking with the service bureau that will be printing CONTRASTMIXTURE the negative. The printed steps of the Standard 21-Step Tablet It is important to first determine the contrast mix (I will that lap over the clear substrate will show two steps be referring to the Na2 method discussed earlier in this merging up to half a stop (one step) lower than the book) you wish to use since the Standard Printing Time, printed steps not lapped over the film. Thus, you can Standard Color Density, and the Process Adjustment adjust your Standard Printing Time accordingly for Curve are dependent upon this variable. This is the the negative substrate you are using. You may have to reverse of the method used when working with adjust printing times until you duplicate this using your traditional negatives, since the density range of the materials and light source. If you change to a different traditional negative is predetermined. brand of substrate, then you should recalibrate the In general, it is best to start with the lowest contrast standard printing time. mix when calibrating. Doing so tends to reduce digital Be sure to save the printed Standard 21-Step Tablet artifacts in prints and establishes a boundary in for reference in the following steps. calibration regarding the standard Color Density Range required. This is true both with negatives from THE DIGITALNEGATIVE DENSITY RANGE color capable devices and imagesetters. With image- setters, since the only control available is the Process The standard definition of density range of a traditional Adjustment Curve, the low contrast mix will reduce the negative is found in Chapter 3: The Negative. amount of curve correction required. Imagesetter negatives, as mentioned before, have a standard density range that cannot be modified. This density may vary some between service bureaus, DETERMININGTHE STANDARD PRINTING depending on how they calibrate their machines. It is OR EXPOSURETIME most important that they do calibrate their machines The determination of the standard printing or exposure regularly for consistent output. This is a good issue time for digital negatives is the same as Dick Arentz to inquire about. Since the density range of imagesetter has described in Chapter 8: Calibration. The goal is also negatives is fixed, the only means of correcting to determine a printing time where at least two of the them to print properly is by using the Process Adjust- darkest steps merge. I make one modification to the ment Curve. If the imagesetter gives inconsistent method for inkjet negatives. The substrate or film that results, the Process Adjustment Curve will not work inkjet negatives are printed on may have a higher UV accurately. density than standard film negatives, or it may have Inkjet negatives are unique in that the density range a higher base plus fog (B+F). This can be factored in of the digital negative can be varied for any printing to the standard printing time by taking a clear strip of situation. substrate and lapping the Standard 21-Step Test Tablet Once you have determined both your contrast mix over it when printing as shown in Figure E.8. This is not and Standard Printing Time, you can now determine necessary to do when the negative will be rendered with the density range you need for your negative. This will an imagesetter, since the base plus fog of the imagesetter be evident by the print of the 21-step tablet you used in determining the Standard Printing Time. This is easily accomplished by using this same contrast mix and Standard Printing Time to print a Color Density Range Palette in Pt/Pd. The Color Density Range Palette is a series of graduated color swatches. For this example, I am using a variation of green. The color green is set in the color picker with the values Red = 0, Green = 255, and Blue = 0. Green is a mix of yellow and cyan ink. The relative amount of cyan and yellow ink in the printed color can be controlled by increasing the blue value in the color picker from 0 up to 255. For example, a color 196 APPENDIX€ of Red = 0, Green = 255, Blue = 100 would print with more cyan and less yellow. This would provide a negative of less color density than a pure green negative. A series of quarter-inch square color steps, with a precisely graduated change in color from pure green to cyan, can be easily constructed by using the following Color Picker values to fill the steps in the following manner: Red = 0, Green = 255, Blue = 0 Red = 0, Green = 255, Blue = 10 Red = 0, Green = 255, Blue = 20 Red = 0, Green = 255, Blue = 30 Red = 0, Green = 255, Blue = 40 Red = 0, Green = 255, Blue = 50 Etc. Once the Color Density Range Palette has been printed with the calibrated contrast mix and Standard Printing Time, the correct Color Density for this combination is determined by the first step of this Color Density Range Palette that prints with PdPd at paper white. This color, the Standard Density Color, is then used to print the Tonal Palette and subsequent negatives. To make a negative using the Standard Density Color, follow this procedure: PhotoshopR (using a text layer) with the level value each represents (0-255). All steps should be an equal value 1. Open an image file of the Tonal Palette or the image apart. you wish to print. I use a Tonal Palette that also includes a digital 2. Create a new empty top layer and set the mode of version of a 21-step tablet and a smooth gradient the layer to Screen Mode. from levels 0 through 255. These are very helpful in 3. Name the new layer with the values for the Standard the visual assessment of the Process Adjustment Curve’s Density Color. effect on the Tonal Palette and subsequent prints. 4. Using the Color Picker, set the foreground color With this workflow, the Tonal Palette is not to the Standard Density Color values. inverted to the negative state prior to printing as will 5. Using the Paint Bucket Tool, fill the new layer with be done with image files. There is no need to, since you the Standard Density Color. would just end up with the same tones in reverse order and an extra step in the workflow to reverse all the values in calculations. Figure E.9 shows a Tonal Palette with 101 steps. THE TONAL PALETTE The Tonal Palette, the digital step tablet used to THE PROCESSADJUSTMENT CURVE determine the Process Adjustment Curve, is made up of a sampling of the 256 possible printing tones. The Process Adjustment Curve is an adjustment curve The number of tones or steps used to create the Tonal that is applied to a digital image file after all other image Palette should be sufficient so that there are not adjustments are complete. The purpose of this curve significant gaps in densities between the tones. The is to adjust the negative’s relative tonal density such smallest number of tones that would still give decent that the image will print properly with the alternative information would be a 65-step Tonal Palette. This process. This adjustment of the negative’s densities series would include steps of every fourth level from 0 causes the printed tonal values to be linearized, so they through 255, or 0, 3, 7, 11, . . . 243, 247, 251, 255. appear the same as the image displayed on the calibrated I use a Tonal Palette with 101 steps. Label the steps in monitor. There are various imagesetter and inkjet “curves” reach the cell containing Dmin. The graphing of this floating around in cyberspace. However, these “Cookie data will produce a straight-line Turget Log Density. Cutter Curves,” as Dick Arentz calls them, are usually If you are using a scanner instead of a densitometer, more frustrating than helpful. I often hear someone make a good scan of the Tonal Palette and then use say “I tried so-and-so’s curve and it worked great!” Levels to set the Black point equal to the darkest step Well, sure it did, sort of. All Process Adjustment Curves and the White point equal to the lightest step. With the have roughly the same shape. The curve is a reverse “S” scanner method, you use the same system as with the shaped curve that opens up the shadows and adds densitometer, except the values will be in tonal levels texture to the highlights of the print. It is easy to prove from 0 through 255 instead of log values. Remember, that such generic versions of a curve will only work best O=black and 255 =white. This is a very simple by chance. What paper and contrast mix was the curve representation of the scanner method. I have a more based on? What humidity level? What workflow? What involved process that I use that is quite accurate, but it alternative process? Determine your own custom curve is too lengthy to describe in this appendix. for your workflow and avoid wasting fine paper, Now graph the two columns. The x axis represents expensive chemicals, and your time. the input densities of the 101-step Tonal Palette. The There are some workflows that apply this curve to y axis shows the reflective densities of the print made the image file in its positive state. I prefer to develop the from the Tonal Palette steps. The values plot as a curve. curve and apply it to the image file in the negative state. You will also see a straight line connecting the endpoints Either method will work and result in the same print. of the density curve. This straight line represents the However, I find it much easier to think of how I want target density of the Process Adjustment Curve, or how to change the negative’s tonal densities to affect the the densities of the Tonal Palette will print after the print densities. This also keeps separate the two distinct proper Process Adjustment Curve has been applied. workflow segments of image file preparation and nega- The basic idea behind the graph of actual printed tive preparation. densities and target densities is fairly simple (FigureE.lO). Once you have created the Tonal Palette, print it This graph shows the log reflection density values (solid on the film substrate using the printer settings described line) of the readings from a 101-step Tonal Palette previously. Be sure to flip it horizontally first so the printed with palladium without a Process Adjustment information identifying the tonal steps will read Curve applied. The target densities are represented by correctly when you contact print it with Pt/Pd. the straight, diagonal, dotted line. If the proper Process Print the Tonal Palette with the same contrast mix, Adjustment Curve were to be applied to the Tonal paper, and exposure time you used previously to Palette, the measured reflective values, instead of being a determine the standard exposure time. Be sure to print sweeping curve, would merge with the dotted line of a standard 21-step tablet alongside the Tonal Palette. the target values and become a straight line. This graph Let the print dry sufficiently, since the densities will can be used to determine what the input values and change as it dries. It is not a bad idea to wait until the output values are for a Process Adjustment Curve that following day before taking measurements. will achieve this linearization. Using a densitometer or a scanner, measure the Most output devices print a negative with a values of each step and record them in a column in a maximum of 256 tones. Given the same output device, spreadsheet, from the darkest tone to the lightest. each tone in the negative or the Tonal Palette will result If you are using a reflection densitometer, the values in a specific printed tone in Pt/Pd. Ideally, the printed you enter will be log values with Dmax at the top and tones should be equal values apart, just as the tonal Dmin at the bottom. Next, create a second column values in the Tonal Palette are. But alas, they aren’t- next to the first and fill it with the same values as the not without the appropriate Process Adjustment Curve endpoints as your measured values-Dmax at the top to correct them. and Dmin at the bottom. Now divide the Dmax value Refer to Figure E. 11. If the projected tone at step 7 by the number of steps in the Tonal Palette minus 1. of the Target Density Line as indicated by the horizontal We will call this value Log Increment. The formula is: straight line in the chart to the vertical axis on the left Log Increment = Dmax/(TP Steps-1). Round the value has a log reflective density of X (here it is 1.31), and the to two decimal places. Starting at the cell just below actual printed log reflective density, as indicated by the Dmax, set the value of this cell to Dmax - Log Measured Log Density curved line in the graph, was Y, Increment. The value of the next cell down will then a different value, then the adjustment for that point be Dmax-(2 x Log Increment) and so on until you on the curve can be found by determining what step 198 APPENDIXE

1 6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81 86 91 96 101 101 Steps of Density

FIGURE E.10 PRlNlEd ANd TARC,ET DENSITIESTkE STRAIqkT REd LINE REpRESENlS TkE TARf.,El LO(, DENSITIES dERl\iEd fROM CAltUlAIlVq 106 INCREMENTS iROM DMAXTO DMIN Tkt CllR\td GRFtN [IN[ IS dRAWN iROM Rtf[tCTl\t dENSlTlt5 RE4d IROM A PRlNl Mad€ fRC)RI TkF 101 YSrtp TONA~ PA~ETTF actually printed with a log reflective density of X. It is step 23. To the adjust the density curve to match the Referring to Figure E.lO, it would be about step 23 on linear Target Density Line, a point representing step 6 the horizontal axis. Thus, to adjust this point on the should have an input value equal to step 6 and an output Process Adjustment Curve, the Input Value is equal value equal to step 23. to the tonal value of step 11, and the Output Value is These adjustments will be made by changing the equal to the tonal value of the step that actually input and output values in the Photoshop’ Curves produced a log reflective density of X. Function window. By examining regularly spaced steps, Figure E.ll is an enlarged section of the chart in such as every fifth step, on the Tonal Palette, this method Figure E.9. can provide a series of adjustments that will define the In Figure E.ll, the input of the Target Density Line entire Process Adjustment Curve. Photoshop only step number 6 gave a reflective density of 1.38. For the allows a maximum of 16 adjustment points in a curve, Measured Density curve to produce that same reflective including the endpoints of black (0) and white (255). density, one must project over from that point to the Thus, it is important to use what few points you have portion of the curve that produced that reflective density wisely. The most critical adjustment regions are at of 1.38 and downward to find the corresponding step. each end of the tonal range, the deep shadows and the ’- Target Density for Step #6 Printed at Step #23 1.45 time you make a new negative and print. Should you want to experiment by changing any of the basic 1.38 variables of contrast mixture, exposure time, negative 1.31 density range, or Process Adjustment Curve, you should

1.23 repeat the calibration steps.

1.16 ADJUSTINGTHE IMAGEFILE BASEDON 1.09 THE TONAL PALETTE 1.02 The Tonal Palette, printed in Pt/Pd, with the Process 0.94 Adjustment Curve applied, can be used as a “pre- proofing” aid in planning your negative and print. You can check the tonal values of the image and compare those with the second printing of the Tonal Palette to make sure that the final print will have the printed tones you desire. Cuwes

Channel. RCB 3- CREATINGTHE IMAGESETTERNEGATIVE

Cancel The workflow for preparing an image to create an imagesetter negative is fairly simple. You prepare the image in PhotoshopR just as you would prepare it for making an inkjet print. Remember, there is no way to adjust the overall density of the negative other than by using the Process Adjustment Curve. Once your image is prepared to your satisfaction, < Options... j you do the following: rpi 91 1. Make a working copy of the image file and save it in a folder for negatives. @IPreview 2. Merge all layers of the image, including adjustment ---- layers. ‘“put I lS3 1 *,I, Adjustment Point 3. Size the image to the dimensions requirements of Output Input/Output Values ...... - - - ...... your final negative. iQ1 4. When sizing the image, set the resolution of the LJ image to 300, 400, or 450 ppi for stochastic screens. 5. Based on the desired size of the print, apply final sharpening. 6. Add a digital gradient and 21-step tablet to your file for evaluation. extreme highlights-the toe and shoulder of the curve. 7. Invert the image to the negative state. You will want to use more of your adjustment points in 8. Apply the Process Adjustment Curve to the entire these areas. Figure E.12 shows the Photoshop@’Curves image file. Function window and the input and output values of the 9. Invert image back to the positive state. adjustment point being added to the curve. 10. Convert the file to 8-bit grayscale. 11. If you wish a border to keep brush strokes from printing, set the background color to black and MAKINGA DIGITALNEGATIVE using Canvas Size, add a border of appropriate AND A PT/PD PRINT width. 12. Deliver the file to the service bureau and ask that Now the careful work you did in calibration begins to your file be printed “as a negative on film, pay off! This section describes the steps to follow each emulsion side down, right side reading.” 200 APPENDIX€

CREATINGTHE INKJETNEGATIVE PROCESS EVALUArlON The Process Evaluation focuses primarily on the 1. Make a working copy of the image file and save it standard 21-step tablet. If the step tablet printed with in a folder for negatives. the same number of steps as predicted, you know that 2. Merge all the layers, including adjustment layers. any problems with the print are related to the negative 3. Size the image to the dimensions for your negative or the original image file. Compare this printed step at 360 ppi. tablet with the one printed during the Calibration 4. Based on the desired size of the print, apply final Process-it should be identical to the one printed with sharpening. the second Tonal Palette. If not, then examine the two 5. Add a digital gradient and digital 21-step tablet to and see what process printing variable may have gone your file for evaluation. wrong. 6. If the file is in grayscale mode, convert it to RGB mode. NEGATIVEEVALUATION 7. Invert the image to negative state. The Negative Evaluation is a bit more complex: 8. Apply the Process Adjustment Curve derived during the Calibration Process. The digital 21-step tablet will not print the same as 9. Create a new layer and set the Layer Mode to the Standard 21-Step Tablet. The two step tablets Screen. have different densities at like-numbered steps. 10. Using the Paint Bucket Tool, fill the new layer with The digital step tablet should print with tone at all the Standard Density Color determined during the but the highest step. The standard step tablet Calibration Process. should print without totie in the higher steps. 11. If you wish a border to keep brush strokes from Examine the digital gradient you included next to printing, set the background color to black and the image to see if it printed with smooth tonality using Canvas Size, add a border of appropriate and good, even tonal distribution. It should look width. like the image in Figure E.13. 12. Load the sheet of film substrate into the printer Examine the digital 21-step tablet you included and make sure the emulsion side will be the with the image to see if it printed with even printing side. separation between the tones. It should look like 13. From the FILE menu, choose Print With Preview. the image in Figure E.14. 14. Follow the instructions in the previous section on If both of these indicators look fine, then the Printer Setup and print the negative. Process Adjustment Curve was accurate. If not, compare the print to the second printing of the Tonal Palette to see if the Process Adjustment MAKINGTHE PRINT Curve gave the same results in both cases. If not, you will most likely need to recalibrate the curve. You now have a negative ready to print. Be sure to If the digital gradient and the digital step tablet include a standard 21-step tablet alongside the negative. look fine, examine the printed image. Look for This will be extremely important later in evaluating the results. Print the negative using the same contrast mixture and exposure time that you determined during the calibration process. Remember, changing paper, humidity, or other variables can cause your print to vary from the expected outcome. Be sure to let the print dry completely before evaluating it. A print that appears and feels dry can look different the next day because of the dry-down effect.

EVALUATINGTHE PRINT I divide the print evaluation into three areas: the Process Evaluation, the Negative Evaluation, and the overall Print Evaluation. FIGURE E.14 Tkt PRINIE~DICITA~ Sltp TAbltl blocked up shadows, blown out highlights, or to exactly match the image on the monitor, the prints flattened mid-tones. If you see problems in any will be indistinguishable. The Calibration System is thus of these areas, then examine the original image intended as a starting point. True mastery of the digital file carefully on the monitor. Examine the areas negative occurs when you are able to go beyond the where the print exhibits problems. Most likely perfect curve and use the interaction of printing time, you will see a similar problem in the image. contrast mix, negative contrast range, and the curve This is due to incorrect local tonal values in the to make a print. Then you have reached the point where image file that resulted from an error in correc- you truly have command of the process and are using tion during the Image File Preparation phase, or it creatively-allowing the unique characteristics of the monitor may not be calibrated correctly. If platinum and palladium to emerge and blend with the latter is the case, then recalibrate the monitor. your treatment of the print image.

CHEMISTRYOR CURVE: WHEN TO USEONE ABOUTPRECISION DIGITAL NEGATIVES FOR OR THE OTHER ALTERNATIVEPHOTOGRAPHIC PROCESSES

The resulting print may be exactly what you hoped to The material presented in this appendix is a brief achieve. It may perfectly match your vision of the overview of some of the material that is covered in printed image and have the exact “feel” you were my book, Precision Digital Negatives for Silver and looking for. Or, it may not. If you wish to achieve a Other Alternative Photographic Processes, 0 Mark I. different look and feel in the printed image, then you Nelson 2004. The book, available in PDF format, may want to consider altering the Process Adjustment describes the method in detail and how the system Curve or the Process Chemistry. works with all alternative process. A variety of intricate If you are having difficulty deciding whether to and precisely designed digital palettes for both inkjet adjust the curve or the chemistry, decide whether the printers and other output devices are included that make change in tonal representation you wish to achieve is it very easy to create stunning work with digital possible by adjusting the chemistry. If so, it is better negatives. The system includes methods and targets for to do it this way than with the curve-if the adjustment profiling densities and testing printer settings. A Curve would require a more radical curve. If the adjustment Calculator spreadsheet is provided that facilitates can be made with a less radical curve, then adjust the development of the Process Adjustment Curves and the curve. This rule will give richer tonality in your prints, analysis and comparison of results. More information is since you are destroying fewer tones with the Process available at www.PrecisionDigitalNegatives.com. Adjustment Curve. If you would like to see more photographic work You can easily learn to make a “perfect” Process by Mark Nelson, go to www.MarkINelsonPhoto.com. Adjustment Curve, however, if you stop there, you This manuscript contains excerpts and summaries lose all the wonderful characteristics that platinum/ from Precision Digital Negatives for Alternative palladium prints are prized for. All your prints will have Photographic Processes. The entire content of this the same tonal relationships regardless of what contrast document, including text and illustrations, is copy- mix you use. If you make a perfect curve for each righted by Mark I. Nelson, unless otherwise indicated. contrast mix, which linearizes the printed tones 0 Mark I. Nelson 2004. Thispageintentionallyleftblank Sandy Kiiig

PLATE F.l Onk ON PERIMETERRond. C~EMSON.SC 2002 20 x 24 Pd 204 APPENDIXF

ULTRAVIOLETPRINTING LIGHTS from late fall to early spring because of the shortness of the days and because the sun is so low in the sky. Printing with the palladium/platinum (Pt/Pd) salts It is possible to print in direct sun or in open shade. requires a light source that emits much of its radiation It should be noted that with most processes, images of in the ultraviolet (UV). A range (320 to 400 nm) and in greater contrast will result from printing in the shade the violet and blue range up to about 420 nm. Palladium rather than in direct sun. Direct sun is of course much and platinum salts, when combined with those of ferric faster, by around 2 to 4 stops. oxalate, are also very sensitive to ultraviolet B rays between 254 and 313 nm, but sources of this type BALLASTEDHID LAMPS(MERCURY VAPOR should be avoided because of the severe risk of skin cancer and cataracts. It should also be noted that AND METALHALIDE) approximately 95% of ultraviolet B light is absorbed Ballasted HID lamps are commonly available in sizes by the ordinary plate glass typically found in contact from 175 watts up to 1000 watts. Such lights have a printing frames and vacuum easels; so in practice, most discontinuous spectrum, but much of the radiation they UV B radiation is useless to palladium and platinum produce is in the useful ultraviolet A range. printers. Ultraviolet C is radiation in the 200 to 253 nm Large HID lamps of 1000 watts are an inexpensive range. Lights in this wavelength are produced for the option for alternative printing. To set up an HID unit purpose of sterilization and for killing bacteria. They you will need what is known as a Luminaire- can be extremely harmful to humans at medium and a complete lighting unit consisting of a lamp, ballast, high levels of exposure. Such light sources should be and reflector. For a standard 1000-watt Luminaire, the absolutely avoided for printing with Pt/Pd. They are ballast will be American National Standard Institute extremely dangerous to use, and ineffective as well (ANSI) specification M47 for metal halide lamps or because virtually all of the radiation below 253 nm H36 for mercury vapor lamps, with a Mogul E39 base is absorbed by ordinary plate glass. Above about for the lamp. The reflector for this unit will typically be 436 nm, the sensitivity of both palladium and platinum 23 inches in diameter. The size lamp required for this is extremely small. application is designated BT56, which is 56-eighths of When using the UV light sources recommended in an inch in diameter. this book, no extraordinary safety features are required The fixture is very easy to assemble and set up. since most of their radiation is in the UV A range, The ballast supply voltage, which is known as a Quad which is much less harmful than W B. However, Tap, has several wires coming out of the unit: one green a few prudent safety steps are advised. One should avoid for ground, a common (white), and four black wires, direct contact with the UV light by wearing glasses one each for 120 VAC, 208 VAC, 240 VAC, and designed for protection from UV light,l and the light 277 VAC. Have an electrician connect the unit to an itself should be covered or shielded. extension cord rated for the amperage for your outlet. There are many sources of UV light: the sun, high You will need to suspend the unit about 30 inches from intensity discharge (HID) mercury vapor and metal the printing frame in order to get even coverage over halide bulbs, fluorescent tube banks, and plate-burners a circle of about 22 to 23 inches. The 30 inches is manufactured for the graphic arts. Any of these light measured from the light pod at the tip of the bulb to the sources is capable of giving good results in palladium plane of the negative to be exposed. and platinum printing. Metal Halide lamps are available with Kelvin ratings from 3200 to 6200K. In general, lamps with a THE SUN higher Kelvin rating radiate more energy in the UV and violet range. Although these lamps are broad spectrum The sun is one of the strongest sources of ultraviolet and radiate considerable energy outside of the useful light, but it varies greatly in intensity according to UV and violet zone in actual practice, I found them to season, time of day, atmospheric conditions, and print about as fast as the NuArc 26-IK platemaker, with geographic location. Its output is especially consistent about the same area of even illumination, when set up at on clear days between 10 a.m. and 2 p.m., but in many about 30 inches from the printing frame. locations in the United States printing is not possible Once you screw in the bulb and turn on the power, the lamp will need about 2 minutes of warm-up time to ' A full line of UV blocking glasses is available under the name Solar reach full output. And, if you shut the lamp off, you will Specs. See uiii'iii.soI~r-specs.cont. need to wait a minute or so for the lamp to cool before it will restart. Unless you have a light integrator, the best the deep violet at 405 nm, and virtually none above way to use the lamp is to turn it on and allow it to reach 435 nm, as all longer wavelengths are highly maximum output before beginning your exp0sure.l blocked. Since the blue filter blocks some useful exposing light, BLB tubes print slightly slower than BL tubes, although the difference is very small. UV FLUORESCENTTUBE BANK 3. Super Actinic: SA tubes emit most of their radiation A bank of black light (BL), black light blue (BLB), in the UV and violet region between about 380 to Actinic, AQUA, or Super Actinic (SA) fluorescent tubes 480 nm, peaking at around 420 nm. is an excellent source of ultraviolet light. UV tube banks 4. AQUA: AQUA is another aquarium tube, made by are very fast, provide a large area of even illumination, Voltarc, very similar in spectral output and printing produce constant output almost immediately after being characteristics to the Super Actinic. turned on (especially when using electronic ballast), and Is there a best tube for printing in palladium and may be switched on and off with no delay. A fan should platinum? Some experienced printers who use the SA be used to cool the tubes because if they get warmer than and AQUA tubes claim they are faster than the BL about 100‘ F, the light output decreases significantly. and BLB for printing palladium/platinum. My own tests, For maximum efficiency, the tubes in a UV tube however, have consistently indicated that when com- bank should be spaced as closely together as practical, paring tubes of the same size and output, the BL tubes certainly no more than 1/2 inch apart. However, since print slightly faster than all others. Nevertheless, the the inverse square rule of point source lights does not actual printing differences between these tubes in terms apply to large, diffuse light sources like W tube banks, of printing speed is so small as to be virtually one will find that there is little to be gained by placing insignificant. Many variables affect printing speed: the printing frame very close to the tubes. In practice, distance from the bulbs to the printing stage, tempera- one will find that there is very little difference in printing ture and age of the bulbs, wattage, and type and power speed of a UV tube bank when the distance from the of ballast. tubes to the printing frame is 3 inches as when it is 8 inches. For ease of operation with printing frames and BALLAST vacuum easels, I recommend a distance of about In actual practice, it will be found when comparing 6 inches. UV tubes that the type of ballast is more important than Four types of fluorescent tubes are useful in the type of tube. There are two main types of ballast: palladium and platinum printing: 1) Black Light tubes, magnetic and electronic. Electronic ballast has many which peak at around 350 nm, 2) Black Light Blue, advantages, not the least of which is the fact that it will a shielded light similar in output to the BL, 3) Super generate between 10% (T12 tubes) and 30% (T8 tubes) Actinic aquarium tubes that peak at around 420 nm; more lumens per watt than magnetic ballast, which and 4) AQUA tubes, with almost identical output to SA. can, of course, result in a lot more UV radiation and 1. Black Light: BL tubes emit most of their radiation faster printing times. Electronic ballast also gives a more at between 350 and 370 nm, but they also emit quite constant output and runs cooler. a bit of light in the deep violet and blue-violet range. They are available in a wide range of sizes, including both 24 inches (20 watt) and 48 inches (40 watt). BUILDINGYOUR OWN UV PRINTER My tests indicate that the BL is the best all-around tube for printing with the palladium and platinum You can buy a factory-built UV printer from Edwards processes. Engineered Products (Source: EE), or if you are reason- 2. Black Light Blue: BLB tubes also emit most of their ably handy, you can construct your own. Good plans radiation in a peak at about 350 to 370 nm, but it are available in several books (Nadeau, 1994; Sullivan is filtered with a tube made of dark violet that and Weese, 1998) and at the Edwards Engineered makes the light very dim to the eye; however, the Products Web site. See also my article on UV light filter is almost entirely transparent to useful UV sources at i~nblinkingeye.cotnlArticleslli~htllight.htn~1. light. BLB tubes emit very little radiation above The major cost of such a project will be the tubes and ballast, which together should account for between ’. See Sandy King, “Ultraviolet LiSht Sources for Printing with 80 to 90% of the entire project. The total cost will vary Alternative Processes,”r~rzl~/itikitzge~e.cut~i/Artrc/es/Li~~~t//I~ht.htrn/.depending on choice of tubes and ballast, but one should 206 APPENDIXF be able buy all of the materials necessary for a 10 to 12 digital, this is a very good time to purchase used bank of 24-inch tubes that will provide even coverage plate-burners. For example, NuArc 26-1K and 26-1KS for prints up to 16 x 20 inches for around $250. plate-burners that sold new for $1700 to $2200 just The cost would be much greater to construct a unit a few years ago are available on the used market for with high output (HO)or very high output (VHO) tubes just a fraction of the original selling cost. The source for due not only to the extra cost of the tubes but also to the this estimate is the completed auction section on eBay. fact that heavier ballast is required than with standard The same is true of high quality plate-burning equipment wattage tubes. by other manufacturers, including Olec. (Source: 0)

T u B E NOM E N c LATu R E TESTINGOF UV LIGHTSOURCES For those contemplating building a W printer with fluorescent tubes, here is a little information on the In preparing data, I ran a series of tests using sensitizers nomenclature of fluorescent tubes. They are usually of pure platinum, a mix of palladium and platinum, designated by a series of letters and numbers. For and pure palladium with three different W fluorescent example, the GE Black Light Blue tube carries the tubes and with a NuArc 26-Ik platemaker with a designation F20T12.BL. USHIO metal halide lamp. The lights tested were: The F stands for fluorescent. 1. 24-inch Philips Super Actinic, TLK/03, 20 watts The next number, 20, indicates the wattage of this 2. 24-inch Sylvania BL (Black Light), 20 watts particular tube. 3. 24-inch Sylvania BLB (Black Light Blue), 20 watts The T number indicates the diameter of the tube 4. NuArc 26-IK, with USHIO Metal Halide Lamp in eighths of an inch. A T 12 tube, for example, is 12/8 or 1 1/2 inches in diameter. Spectral Power Distribution charts for these four The letters describe the lighting characteristics sources of UV light are reproduced in Figures F.l of the tube. In this case, BL designates a Black through F.4. The tests with all three of the fluorescent Light tube. tubes were made with a four-tube bank using the same Tubes sometime carry further indicators, such as electronic ballast unit. IS (Instant Start), RS (Rapid Start), or even letters showing the kind of usage for which the tube is intended, for example, R for reptiles, A for TEST CONDITIONS Aquarium, etc.

Standard wattage tubes vary in wattage according 1. The exposing negative was a Stouffer TP 4 x 5 step to size. For example, a regular output 24-inch tube is wedge. rated at 20 watts, while a regular output 48-inch tube 2. Tests were repeated three times to verify consistency of the same type is rated at 40 watts. Some fluorescent and to ensure that small fluctuations in voltage did tubes are also available in HO and VHO. When using not skew the results. tubes of the same type and wattage, there is no difference in printing characteristics between a 24- and 48-inch tube. 0.30 0.25

0.20

PLATE#BURNERS,OR GRAPHIC ARTS PRINTERS 0.1 5

The light source of modern plate-burners is usually a 0.10 metal halide discharge lamp, but some older units may 0.05 be equipped with mercury vapor, carbon-arc, or pulsed- 0.00 xenon lamps. Plate-burners, which usually come with 300 350 400 450 500 550 600 integral vacuum frames and light integrators, make NANOMETERS excellent UV printers for palladium platinum printing. Because of the changeover in the prepress industry to FIGURE F. 1 Sptc TRA~POUER DisrnibLiioN fm Philips TLKI03 Distance from tubes to printing frame was 6 inches for the fluorescent tubes, and standard printing distance for the NuArc 26-IK. 6. Three different sensitizing mixes were tested: 1) 100% platinum; 2) 50% platinum plus 50% palladium; and 3) 100% palladium. Each was mixed 1:l with a 25% solution of ferric oxalate. 7. Development of all tests was carried out in a 30% solution of potassium oxalate, used at 120" F. 300 350 400 450 500 550 600 NANOMETERS

GENERALREMARKS ABOUT RESULTS

Several conclusions can be drawn from a comparison of the three families of curves. First, there is very little difference in printing speed between the four UV light sources tested. Second, contrast, as measured by exposure scale (ES), is virtually identical with all of the lights. Third, palladium is by far the dominant metal when it is mixed in a 50/50 ratio with platinum. And finally, pure palladium is a lot faster than pure platinum. Further analysis of individual curves is required to discern the subtle differences between light sources. 300 350 400 450 500 550 600 Table F.l highlights the slight differences in speed. For NANOM ETE RS the purpose of this analysis the Speed Point of PtPd is taken to be the point on the curve where 90% of Dmax is reached. Although the differences are quite small, the BL tubes print faster than any of the other lights with 0.30 pure platinum, pure palladium, and with a combination of the two metal salts. The higher the number expressed 0.25 in log units, the faster the exposing light. 0.20

0.1 5 0.1 0 CONCLUSIONS 0.05

0.00 All of the UV light sources used in testing for this article 300 350 400 450 500 550 600 are capable of excellent results with any of the processes. NANOM ETERS They all print with about the same contrast, and although the BL tubes are on the whole faster than the FIGURE F.4 SPECTRALPOUER DlSTRlbUTlON fOR NUARC26-IK. others, the practical difference is very small. wirk USHI0 META~HnlidE LAMP Nevertheless, it was noted that the Super Actinic curve has much less toe and, for that reason, has a 3. The same paper, Platinotype, was used for all tests. longer area of straight line than the curves produced 4. All tests were carried out with room conditions at by the other lights. This characteristic of the SA is true about 70" F and 55% relative humidity. with pure platinum, pure palladium, and with a combina- 5. All tests received 5 minutes of exposure. The tion of the two metal salts. Although I don't know the fluorescent tubes were allowed to warm up for physical cause of this phenomenon, it is most likely due 1 minute prior to the beginning of exposure, while to the fact that the Super Actinic tubes produce most the NuArc was allowed to warm up for 2 minutes. of their useful radiation at a different wavelength than 208 APPENDIXF

THE QUESTIONOF SHARPNESS

There have also been claims made that the prints made with plate-burners and other HID lamps are sharper Platinitnil than those made with fluorescent tubes. In my own UV Source Platinum Palladiuni Palladitrin work, in which I use both types of light sources with SA 0.60 0.70 0.92 vacuum frames, I can see no difference in apparent BLB 0.55 0.80 0.85 sharpness. When using a vacuum frame, perfect contact BL 0.65 0.95 0.95 is ensured between the negative and paper during NuArc 0.52 0.82 0.88 exposure. On the other hand, when making large prints in a contact printing frame, where it is very difficult to maintain good contact over the entire sur- face area of the negative and paper, I have found that prints made with HID lamps often have greater apparent sharpness than those made with fluorescent tubes. The reason is obvious. Most contact printing frames in large sizes are not capable of maintaining perfect contact between the negative and printing paper, and a lack of contact leads to scattering of the light (and loss of sharpness) with a diffuse printing source where many of the light rays pass through the negative at very low angles. With a semi-collimated unit such as a plate- burner-where the rays pass through the negative at relatively high angles- there is much less scattering of light.

1.5 UV BLOCKERS - 1.2 WINDOWGLASS 0.9 Ordinary window glass, or crown glass, absorbs a

06 significant percentage of radiation in the useful UV A range. I measured the transmission loss of ordinary glass 0.3 in one of my UV printers, fitted with ordinary plate - glass, by taking a reading in UV mode through a Gretag 0.0 D-200 I1 densitometer, with sensitivity at 373 nm. The density readings transmitted to a loss of log 0.16 for a 1/4-inch thick piece of glass. That figure represents a loss in transmittance of around 30%, which amounts to a speed loss in printing speed of a full 1/2 stop.

SPECIALTYGLASSES the other lights: The BL and BLB tubes, and the NuArc 26-IK metal halide lamp, produce most of their UV Some specialty glasses allow a higher percentage of radiation at around 36.5 nm, while virtually all of transmittance of UV light. Starfire is a glass that is the radiation of the Super Actinic tube is in a spike advertised to transmit between about 3 to 6% more at around 420 nm. In an effort to better illustrate light than regular glass in the range of 400 to SO0 nm, this characteristic, I have isolated from the family of and perhaps an even higher percentage below 400 nm. palladium curves shown previously just the curves I acquired a few sample pieces of Starfire glass and made by the Super Actinic and the NuArc 26-IK, as made some tests with it in a small contact printing seen in Figure F.S. frame. In my tests I was not able to detect any difference in printing speed between the Starfire glass and ordinary It is almost certain that one could reduce printing crown glass with either dichromate or iron processes. times slightly by replacing the ordinary plate glass in It should be noted that the glass used in my tests was our vacuum frames or contact printing frames with only 1/16-inch thick, and if one were to make the same specialty glasses that allow the transmittance of a higher test in a large printing frame with 1/4- or 3/8-inch thick percentage of UV radiation. However, these glasses tend glass, the results might very well be different. However, to be quite expensive and it is debatable whether or not even assuming that the Starfire glass increased trans- the considerable additional expense can be justified on mittance in the UV range by 10% over regular glass of a practical basis. I have considered the matter carefully the same thickness, this would translate into a speed in my own case and determined that it is not worth gain of less than about log 0.5, or 1/3 of a stop. the trouble. Thispageintentionallyleftblank Stan Klimek

21 1 212 APPENDIXG

Having spent a couple of decades in commercial photography in Los Angeles, I started to become bored Solution A Elon (Metol) 30 g and decided to re-examine what photography meant to Sodium sulfite, desiccated 400 g me. In 1991, I came across platinum printers John Water 4 liters Richardson and Norma Smith, who were giving work- Solution B Kodalk (balanced alkali) 40 g shops on platinum printmaking. Platinum printing Water 4 liters reaffirmed my love for photography by combining it with printmaking, also a fascination during my art school days. Once again I had the energy to create new work, but this time it would be all mine, with its own signature. One of the rewards of a lifelong pursuit of the for a grade 0 or 1 on silver-based paper is suitable. For arts is the accumulation of the artist's life experiences my purposes, I use HPS, which is rated ASA 400, at in his work, creating a fingerprint as unique as the artist a working speed of 160. After unloading my exposed him or herself. film into a JOBOR drum, I presoak for 5 minutes in Platinum printing has been in existence for over 100 water at 70' F. To develop, I use the two-bath years, but it fell out of favor in the second decade of the compensating method (Table G.l). Solution A is twentieth century. Over the past 15 years, however, it Kodak D-23, which is similar to Kodak D-76 without has experienced a revival through a small and dedicated the hydroquinone, an accelerator for the highlights. coterie of artists from around the world, Dick Arentz Solution A develops the values. Solution B is an alkali chief among them. Having studied the original literature bath that works further into the shadows without on platinum printing technique, these contemporary disrupting the highlights. The film is developed for 7 printers have engaged in extensive testing of new techni- to 10 minutes in solution A and 3 minutes in solution B. ques and modern materials, sharing discoveries and building on each other's findings. As a result, the plati- num/palladium process we know today is safer, more Du PLICATING reliable, and more successful than the early process on which it is based. In order to contact print a negative at other than its Like most people, I was sold on printing in modern original size, the negative must be duplicated to the platinum when I made my first print in 1991. In my size at which the image is to be printed. In the past case, I used a 665 negative from an old Polaroid 180 I have duped traditionally by making a pyro positive camera, slopped the solution with my foam brush onto on Bergger BPF 200 film, and from that, a negative on Crane's Ecru and slapped on a negative-wow, I was APHS litho film. The method I use was developed by hooked! It was a delicate, warm-toned image that Stuart Melvin. gracefully melded with the paper. Years later, I reprinted More recently I have had success with the digital that image and compared it to the first. I realized how duping process with a stochastic negative output on my printing skills had improved; still, I love that first the Agfa Imagesetter, with the help of Peter Ellzey of print. Copygraphics in Santa Fe (Source: CG). After adjusting There are many factors that must be controlled to the RGB scan file in Photoshop'R and converting to make a good platinum print. They must be tested and grayscale, I interpolate the file to the desired resolution refined for each image printed. It is a time-consuming, with Genuine Fractals" (Soztrce: AG). I have used laborious, and expensive process, made worthwhile by Telegraphics Software's Rustus plug-in for Photoshop the result. To minimize effort, keep detailed notes of the to create the stochastic screen for the imagesetter as variables tested. Also, by standardizing procedures, a workaround for Photoshop's 30,000 pixel limit. many of the problems that can waste a day of printing With the release of Photoshop CS in October can be eliminated. 2003, Photoshop'sR pixel limit was increased to 300,000 x 300,000. As of this writing, however, I am unaware of any raster image processor (RIP) that is yet THE NEGATIVE able to take advantage of that change. Because a stochastic negative is printed using The negative used for printing in platinum/palladium random dots instead of the gridded dots of the more must be more contrasty than that used for silver common halftone negative, it is more like film. As an printing. As a general rule, a negative that is optimized example of the capabilities of this technology, recently Appmdix c E~EMENTSOf PkliNUM PRiNTiNq 21 3

I digitally created a 20-inch negative from a 3Smm Clearprint vellum: It demonstrates sharp detail and Tri-X film original for a client. The imagesetter output has great blacks, but it must be handled delicately. retained the look of a similarly enlarged film negative It is translucent and economical. and grain structure, with no discernable digital dot and Arches Platine: It has good blacks, coats well, is very no moire in multiple registrations. Additionally, digital white, has tight weave, and is good for large prints duping has an important advantage over film dupes: and multiple coats. It has been very inconsistent. One negative can be taken in-camera and used for any printing process, silver or alternative, by modifying it Additionally, most modern papers have buffering in Photoshop and applying the appropriate character- agents added to them that can interfere with the istic curve. platinum printing process. One paper in particular, Rives BFK, has so much buffering agent added that it feels chalky when handled. To remove them, soak the MAT E R I A LS paper in a 1% solution of oxalic acid for 3 minutes and PAPER dry naturally. This presoak also adds a slight acidity to the paper, which will improve the blacks. Paper is one of the most problematic elements of the platinum printing process. Papers used for printing in platinum are not made for this process, with few PLATIN u M/ PALLADIu M SOLUTION exceptions (Platine being one). (See Chapter 5: Paper.) They can contain sizing and additives that interfere with The basic solution used to coat paper for a platinum/ the platinum printing process. Also, it can be difficult palladium print consists of metal salts in solution with to get in the size or weight required, when needed. ferric oxalate. Other substances can be added to the Papers vary in how they print; the same paper can even solution to accomplish various objectives (e.g., ethylene vary among batches or weights. They are discontinued diamine tetraacetic acid [EDTA] to aid dissolving), but by the mills without notice, or their formulations are I use only a contrast agent. Experimenting with the changed without announcement. They often harbor chemicals and ratios is crucial in improving platinum unknown paper gremlins that ruin prints for reasons printing skills. that can never be ascertained. In comparing the metals, palladium produces a Printing in platinum is most often done on water- warmer tone, lower contrast, and a wider range of color or printmaking paper. Each paper has a distinct values. It does best in the mid-tones and the shadows of signature. Exploring the various papers can take a lot the print. Platinum has a cooler tone and more contrast. of time and be a source of frustration, but is critical It excels at bringing out delicate highlights but has a in honing printing skills. Experiment, find one or two tendency to grain up when platinum is used in a greater suitable papers, and come to know them well. than I:1 ratio in the solution. I almost always use a S:1 The following outlines my own experience with ratio of palladium to platinum; I find this formula gives papers commonly used for platinum printing: a warm tone with the range of values I seek. I use Na2 to increase contrast and choose papers or developers to Fabriano Artistic0 Extra White (aka Fabriano Uno): change tone. (See Chapter 8: Calibration, and Chapter It produces medium blacks, sharp detail, and coats 9: The Platinum and Palladium Print.) and clears easily. It is readily available and has I use a 1:l ratio of ferric oxalate to metal. I always a tight weave, good for large prints and multiple mix the ferric oxalate from powder the night before the coatings. next day’s printing. Caution must be observed with the Rives BFK: It is noted for a beautiful texture and powder as it can become airborne; use a respirator. is challenging to work with, but worth the effort. Mix in a low light environment, preferably with a low This paper is readily available. watt tungsten bulb. I use a formula of 26 grams ferric Stonehenge Rising: It coats well, clears well, has oxalate to 100 ml of distilled water with no other a reddish brown warm tone and has a low cost. additive. Shake it for S seconds in an amber bottle and allow it to set up (become clear) overnight at room Platinotype: It coats well, has good detail and good temperature or with a microwave oven dedicated to blacks, and is lightweight. chemicals only. After shaking, loosen the cap of the Somerset: It has a heavy texture, good blacks, and bottle and microwave at medium power for 4.5 seconds. coats well. Tighten the cap and shake for 5 seconds, then loosen the 214 APPENDIXG cap and put it back in the microwave for 45 seconds. Monitor to prevent boiling. By this method it will clear in about an hour, but it will still be hot. Cool it to room temperature before use. Extending Solzition for Coating In milliliters In drops CONTRASTCONTROL For contrast control, I use Na2 (sodium chloroplati- Solution Water to add Solution Water to add 2 nil 0 40 drops 0 nate). Na2 works to increase contrast without the 3 in1 1.5 rnl 60 drops 30 drops graining found with other agents. (See Chapter 4: 8 ml 3.5 ml 160 drops 70 drops Chemicals.) I keep on hand dilutions of 2.5, 5, 10, and 12 ml 7.5 ml 240 drops 150 drops 20%. To determine the amount of Na2 to add to the metal solution for a specific print, run a test strip without Na2 in the ferridmetal solution to estimate with a 4% solution, the platinum print started to take exposure time (many platinum printers use a densit- on a reflective quality. A 2% solution showed no benefit ometer for this task; prefer to use my eye). Using the I to the print, but a 3% solution was just right. However, time determined from that test, expose a part of the print 2% seemed to work well for Stonehenge, while 3% was with a full range of values with a solution that contains too much. no Na2. Allow that test to completely dry down, either naturally or with blotting and a dryer; a dry print 1. Preshrink paper at 120” F for 30 minutes with a 1% appears cooler and about 15% darker when it is fully solution of oxalic acid added to the water. dried down. 2. Lay down the warm paper on a sheet of glass and When the print is dry, judge how much is needed blot the excess water. The paper should still be to increase the contrast. Knowing the amount of Na2 warm and wet. that is needed to add a specific degree of contrast is 3. Warm gelatin solution to 125” F. Add formalin to the product of experience. As a rough guide, if the the gelatin solution at a 150 ratio. This works out contrast of an 8 x 10 print is close, add one drop of to roughly six drops of formalin to 10 ml of gelatin 20% Na2 solution; if the contrast is far off, add two solution; for an 11 x 14, add 9 drops of formalin to drops of 20%, expose, and evaluate. It is helpful to write 15 ml of gelatin. Use caution when handling on the back of the print the variables being tested. formalin; it is a formaldehyde solution and therefore Repeat the testing process until the contrast is correct. flammable and toxic with a strong pungent odor The bad news about this testing process: It will only that will irritate eyes and throat. It is nasty stuff, but provide a starting point, as the full sized print often the most effective alternative for hardening the requires further contrast adjustment. The good news: A gelatin. negative perfectly crafted for platinum printing may not 4. Brush the solution onto the paper with a good need any Na2 at all. quality, flat, 4-inch watercolor wash brush that Besides adding a contrast controller to the platinum has been warmed in water and shaken of excess solution, I also extend it with distilled water. This wetter water before use. A smooth even coat is critical; solution makes for a smoother coat. Some guidelines for anything short of that can ruin a print. Technique amounts to add to the ferric oxalate/metal solution are is all-important. listed in Table G.2. a. Dip the brush in the solution. The brush will soak up about 7 ml of solution on the first dip. b. Starting at the top, brush across the entire sheet horizontally; the coat will be thick. Re-dip the TECHNIOUE brush if the coating becomes noticeably SIZING thinner. c. Next, without recharging the brush, smooth Most advanced platinum printers don’t size unless using the horizontal coat with vertical strokes. a specific paper that requires it. When sizing is done, d. Lastly, lightly feather the coating with 250-bloom gelatin in a 2, 3, or 4% solution is used. horizontal strokes across the entire sheet. Each paper must be tested for the correct solution. For 5. Allow to dry down naturally. Use the sheet within example, I found that on Fabriano Artistic0 EW sized a few days. H u MIDIFYI NG covering any fugitive solution spots that might have found their way to the print border during Introducing moisture into the paper before coating coating. improves blacks and makes the coat more consistent 2. On a glass light table, place the Rubylith” glossy and easier to lay down. I introduce 75% humidity from side up. Place the negative emulsion side up on the an ultrasonic humidifier for 10 minutes prior to coating. Instead of humidifying the entire studio, I built a box Rubylith’$’and center it with a ruler on all four sides. that measures 40 x 28 x 16 inches; this large box Tape all four sides down with either lithographer’s humidifies more quickly and permits more control of tape or black photographer’s tape. the moisture content of the paper. It also accommodates 3. Turn the taped sheets over so that the red mask paper for large prints and prevents the studio from is facing up. The negative should be centered on becoming a sauna. Introducing humidity will increase the RubylithR and oriented as the print will be. the contrast and narrow the value scale for some papers; 4. With the light table on, place a cork-backed metal testing is recommended. Humidity gauges are readily ruler on an edge. Take an X-ACT0 knife with a available at general merchandise stores at low cost. new #11 blade and lightly cut through the red mask without cutting the mylar, scoring down the ruler. This will take a bit of practice to master. Overcut the corners by 1/4 inch; it is difficult to get a perfect COATING corner without overcutting. A good coat of platinudpalladium solution is even 5. Cut the remaining three sides and gently lift up the more critical than a good coat of sizing. I still hear in red mask at a corner with the tip of the knife. Once my mind every time I coat: “Brush slowly, brush lightly, the corner is up, grab the red mask and strip away brush wet, and take your time brushing,” Stuart the cut area. Melvin’s coating mantra. There are many mistakes to 6. Cover the overcuts on each corner with a 1-inch be made with laying a coat. It may be laid down too strip of Rubylith’“ tape at a 45-degree angle to each quickly or too slowly, too softly or too hard, and with corner. This Rubylith”/negative sandwich will hold too much or too little solution. Another problem may together well and can be stored as is for future be the paper. The paper may not have enough internal printings. If brush marks are desired at a later date, sizing or may not be properly humidified. Most coating simply strip off the red mask. problems, I believe, are either from the paper or the coating technique, not the chemistry. Now that the negative is ready, it is time to coat. I coat on a light table lit from below with low 1. Dip a 4-inch Richeson brush in distilled water and wattage tungsten bulbs. This allows evaluation of the remove the excess by dragging it across the lip of the coating while it is still wet. It shows coating over- bowl. After two easy shakes, the brush is ready for saturation, undersaturation, brushing problems, and coating. flaws in internal paper sizing. These problems cannot 2. Pour a bead of the ferridmetal solution at the top of be fixed at this point, but the lighting will reveal errors the area to be coated. Brush it quickly in a rough in the coat that can be corrected on the next go. Also, rectangle 10 to 15% larger than the print area. occasionally these errors will not be visible on the final 3. After the rough in, slowly move in horizontal and print and the paper can be salvaged in time to produce vertical patterns until the coat appears smooth, a fine print. using only the weight of the brush. To show a clean print edge instead of brush strokes, 4. Blow dry on a medium-warm setting or with use Rubylith@ D3R. Rubylith‘“ is a mylar with a fans. Different papers have different drying lacquered red orthochromatic mask that is easily requirements. Stonehenge should set-up for a separated after cutting. The RubylithR is clear, tough, few minutes before drying. Rives BFK should be and stable, and the coating is translucent, enabling brushed and dried quickly. Fabriano Artistic0 has precise stripping in of the negative on a light table. a better black if dried immediately. If masking for My procedure for registration of the negative to a clean edge, blot the edges of the coat with tissue. RubylithE is as follows: This will make clearing easier and erases the small 1. Cut a piece of RubylithR larger on all four sides than faint gray line that appears on the more absorbent the paper being used. The extension will help with papers. quick registration in the exposure unit and for 5. Humidify again at 75% for 8 to 10 minutes. 216 APPENDIXG

After these steps, the paper should have a translu- 1. Mix the developer. It is preferable to cent and smooth orange coat that appears flawless on overestiniate the amount needed to develop a the light table. It is now ready for exposure. print than to underestimate. If part of the print is not covered in the first pour it could leave a mark on the print that cannot be worked around, especially on a highlight. EXPOSING A quart for an 8 x 10 and 1.5 gallons for a 20 x 24 Exposure equipment for platinum printing is usually should suffice. adapted from equipment designed for a wide range 2. Pour the developer over the print in a of other uses. I use a 36 x 45-inch vacuum frame from tray quickly. Though the latent image is a frame maker and a 1 k metal halide Olite from immediately apparent, develop for at least 3 a commercial printer. I find the metal halide produces but no more than 4 minutes to allow complete better blacks and sharper detail than the fluorescents conversion of the ferric oxalate and to facilitate I have used. clearing. The print should be exposed immediately after 3. After complete development, wash for 10 seconds the post-coating humidification. I believe maintaining in 70~F water. Repeat. humidity in the paper during exposure deepens the 4. Follow with 4 minutes in Kodak Hypo Clear in blacks and increases contrast. In order to preserve the a 1:l ratio from stock solution. moisture in the paper during the exposure process, 5. Wash for 10 seconds in 70- F water. Repeat. I sandwich the coated paper and the negative between 6. Agitate for 3 minutes in a 3% solution of muriatic a piece of mylar the size of the exposure unit's surface acid'-3 minutes exactly. and the glass. Caution must be used that the paper 7. Wash for 10 seconds in 70' F water. Repeat. not be humidified to greater than 85% when using this 8. Soak for 5 minutes in Kodak Hypo Clear in a 1:l technique, because the excess moisture can irreparably ratio from stock solution, agitating intermittently. scorch the emulsion of the negative. To guard against 9. Wash for 15 minutes. this, 1 mil mylar can be placed between the paper and 10. Dry naturally. the negative without interfering with the quality of the print being exposed. Inadequate clearing is a common problem. Besides After laying the coated paper in the frame on the making for muddy highlights, failure to completely clear mylar, register the negative on the paper. Secure the glass a print will cause it to stain over time. It is difficult and start the exposure. Platinum/palladium prints can to judge when a platinum print is cleared; the color be burned and dodged to a maximum 10 to 20%. When of undissolved ferric oxalate is easily mistaken for the exposure is complete, remove the print immediately print tone. In this case, trust the formula instead of the to the developer; it is especially delicate and light sensitive eye. However, a print that has been masked in at this point. Rubylith" as described previously will readily reveal to the eye a poorly cleared print, as it will have a slight discoloration or yellow tint in the border area where DEVELOPINGAND CLEARING the Rubylith" was. I use either potassium oxalate or ammonium citrate to develop prints. Potassium oxalate produces redder, warmer brown tones. Ammonium citrate yields a '. Mttriatic uc-id is an older term for hydrochloric acid. Hydrochloric yellow-brown hue that is cooler than the potassium acid, MSDS 4, is extremely caustic. See the precautions for oxalate's, but it still has a warm hue. When heated, handling and mixing acids in Chapter 4: Chemicals. I have tried different clearing methods and, in some cases, the muriatic acid the tone becomes warmer and deepens. Do not heat the step can be dispensed with if the paper is a tight weave like developer to more than 120 F. This higher temperature Fahriaiio Artistico and Platine. However, with Rives and Stonehenge, will cause varying results, as each paper responds due to their soft weave and minimal internal sizing, the acid is differently to the developer. For example, Stonehenge needed. I have seen no delicate highlight etching occurring from the developed in potassium oxalate heated to 120 F has use of muriatic acid, and it guarantees complete clearing. The clearing agents like Hypo clear, EDTA, and sulfites do a great job a very warm reddish-brown tone, whereas Fabriano in dissolving unexposed ferric, but when combined with an acidic Artistico EW developed the same way will have a cooler etch from an acidlike muriatic, it removes mnst of the remaining tone than the Stonehenge. vestibules of rust. FINI SHI NG ETCHI NG

SPOTTINGOur In some cases, imperfections that lay below the surface of the paper can be repaired. The smallest can be spotted Though Spotone’ is the traditional medium for spot- with Chinese white watercolor. On a heavier weight ting, I prefer watercolors. The dyes in Spotone are less paper with a tight weave, such as Fabriano Artistico, stable than the pigments in watercolors. I have found flaws in the border area can be lightly sanded out with that lamp black with a bit of burnt umber works well for a small piece of fine grit sandpaper. Irregular particles 90% of spots on the platinum print. To prepare, squeeze imbedded in the paper can carefully be picked out with out a small dab of lamp black, mix in the burnt umber the tip of a sharp #11 X-ACT0 blade and lightly with a mixing knife, and let it dry. After it is mixed, mended with a bone burnisher. it can be stored for future use. If dried out, rewet Occasionally a print will be affected by the with a spotting brush that is charged with water. notorious Black Dot Plague. This is characterized by Additionally, Chinese white works on some small dark several or many black dots occurring at random in the spots in white areas. A high quality sable brush, size 3 to 5 coated area of the print. The prints of every experienced aught, works well for spotting out. After careful practice, platinum printer have been infected by this scourge even delicate highlights can be blended seamlessly. at some point, and the cause is unknown. In mild cases, etching the dots out with the tip of a #11 X-ACT0 and spotting with Chinese white helps. If they persist in subsequent prints, a change of paper can help. FILLINGIN Sometimes values can be drawn in using high quality FLATTENI NG artist’s charcoal and a smoothing stump. This can be I flatten prints in a dry mount press between two sheets useful in saving a difficult-to-print image by adding a bit of rag board on moderate heat for 3minutes. Then of value to a small flawed area. The materials necessary I place them under a heavy sheet of plate glass until the for this technique can be found at the art store: sticks heat dissipates. of charcoal in black, burnt umber, and burnt sienna; fine grit sandpaper; a kneadable eraser; and paper WAXING stumps for blending. Waxing a platinum print can deepen the blacks, give 1. Determine what combination of the three hues of a pleasing tone to the highlights, and can impart charcoal sticks will match the tone of the print. a pleasing sheen to the print if done correctly. Waxing Grind up a small amount of charcoal dust with sand is not without its detractors, however. Some do not like paper from the chosen sticks. the look. Others worry that it may not be archival. Still 2. Pick up this blended dust with the tip of a stump and others fret about gilding the lily. Ultimately, the decision remove most of it. Only a slight amount of charcoal to wax or not lies with the judgment of the printer. dust needs to be on the tip. Materials needed for waxing are Gamblin cold wax 3. Lightly test on a scrap of the same kind of paper medium, a 2-inch stencil brush, a stiff shoe polish brush, the image is printed on to get a feel of how much to and a soft shoe brush. To wax: lie down. In this case, less is more. 4. Draw in the flawed area of the print, then gently 1. Tape the print to a sheet of glass with drafting tape. Mask off the edges of the print. (3M Low-Tack smooth it with a stump. Continue to draw and smooth until the area blends into the print. Small Painter’s Tape works well.) mistakes can be corrected with a piece of the 2. Place a light next to the print and position it so the kneadable eraser. Warm it in the hand until it is light falls across the print. This will aid in laying down an even application by allowing the mon- pliable enough to roll out a fine point. Take the mistake out with this point and redraw. No need to itoring of the coat as it goes down. a protect or fix this charcoal dust; it is bonded to the 3. Take quarter-size dab of wax with the stencil paper fibers. brush. Using short strokes, cover a 3-inch by 3-inch area. Smooth that area with the stencil brush twice. It takes practice to become proficient in this Take another dab of wax and reDeat on an adjacent technique, but- the reward for persistence is an invalu- area. Slowly work up the print. Platinudpalladium able tool for finishing that could save a print. prints are tough and can withstand this. When 218 APPENDIXG

finished, examine the evenness of the entire coat of A good way to see the effects of waxing is to lay wax in the oblique light. Make any necessary down a strip of low-tack painters tape down the middle adjustments. of a rejected print and wax one side. This allows direct 4. With the stiff shoe brush, brush out to smooth and comparison of the wax’s effect. pick up the excess wax, using horizontal semicir- cular movements. Keep the brush clean while The quest for the perfect platinum print is similar to working the coat. aiming at a moving target. After all these years, I still 5. Examine the wax coat in oblique light again. If it is learn something new every time I print. Techniques not smooth enough at this point, use the soft shoe I’ve been using become ineffective. Materials change or brush to smooth it out. If it is already smooth another printer comes up with an improved procedure. enough, do not brush further. Overbrushing creates But after I chase it down, work it through, and come a gloss. Remove the tape mask from the print and through with an image with which I am satisfied, I am blend the edge of the wax with your thumb. Let the allowed to relive the moment that I made my first wax set up for 2 days. platinum print. 21 9 220 SOURCES

ANTI STAT Ic So LUTI o Ns CHEM ICALS

MD Modern Solutions. 6370 Copps Ave., Madison, AC Artcraft Chemicals. Box 583 Schenectady, WI 53716 NY 12301 Tel: (800) 288-2023 Fax: (608) 222-2704 Tel: (800) 682-1730 Fax: (518) 355-9121 http://www .modernsolutionsinc.com http://www.artcraftchemicaIs.com j [email protected] ARCHIVALPRODUCTS BL Bryant Laboratory, Inc. 1101 Fifth St., Berkeley, CA 94710 CR Conservation Resources. 5532 Port Royal Rd., Tel: (800) 367-3141 Fax: (510)528-2948 Springfield, VA 22151 http://www.us.chemnet.com/dir/Glass/ Fax: (703) 321-0629 index2. html http://www.conservationresources.com (A good source for bulk chemicals) GA Gaylord Brothers. P.O. Box 4901, Syracuse, NY BS Bostick & Sullivan. Box 16639, 1541 Center Dr., 13221-490 1 Santa Fe, NM 87505 Tel: (800) 448-6160 Fax: (800) 272-3412 Tel: (505) 474-0890 Fax: (505) 474-2857 http://www.gaylord.com http://www. bostick-sullivan.com LI Light Impressions. P.O. Box 940, P.O. Box 787, [email protected] Brea, CA 92822-0787 [email protected] Tel: (800) 828-6216 Fax: (800) 828-5539 (Arentz Kit: One of two suppliers of PtRd coat- http://www.lightimpressionsdirect.com ing solutions; also paper, printing supplies, print- ing frames) PF Photographer’s Formulary. Box 950, Condon, BEYONDTHE ZONESYSTEM (BTZS) PRODUCTS MT 59826 Tel: (800) 922-5255 Fax: (406) 754-2896 VCS View Camera Store. P.O. Box 19450, Fountain http://www.montana.com/formulary Hills, AZ 85269 [email protected] Tel: (480) 767-7105 Fax: (480) 767-7106 (Arentz Kit: One of two suppliers of PtPd http://www.viewcamerastore.com coating solutions) [email protected] QC Quality Camera Company. 382 Trabert Ave., (Also a source for large format film, cameras, and Atlanta, GA 30309 densitometers) Tel: (404) 881-8700 Fax: (404) 881-9010 (Ammonium platinum and palladium salts) CAMERAMAKERS SL Spectrum Labs, Sales Department. 14422 S. San Pedro Street Gardena, CA 90248 KC K.B. Canham. 2038 East Downing, Mesa, Tel: (310) 516-8000 or (800) 772-8786 AZ 85213 Fax: (310) 516-7512 Tel: (480) 964-8624 Fax: (480) 892-4146 [email protected] http://canhamcameras.com (A good source for bulk chemicals) HC Hoffman Camera Company. 19 Grand Ave., Farmingdale, NY 11735 Tel: (516) 694-4470 Fax: (516) 935-0748 CO~TACTPRINTING FRAMES AND FILM HOLDERS hi20301 [email protected] PC R.H. Phillips & Sons. P.O. Box 1281, Midland, AWB AWB Enterprises. 33320 Gafford Rd., Wildomar, MI 48641-1281 CA 92595 Tel: (517) 835-7897 Fax: (517) 839-9745 Tel and Fax: (909) 674-0466 [email protected] http://www.cosmoaccess.net/--awbent WC Wisner Company. P.O. Box 21, Marion, [email protected] MA 02738 BS Bostick & Sullivan. Box 16639, 1541 Center Dr., Tel: (800) 848-0448 Fax: (508) 748-2733 Santa Fe, NM 87505 http://www.wisner.com Tel: (505) 474-0890 Fax: (505) 474-2857 http://www. bostick-sullivan.com SOURCES 9 221

DENSITOMETERS FILM, ULTRA.LARGEFORMAT

DI Diversified Equipment Company, Inc. 7213 JC J and C Photo. P.O. Box 366, Grover, MO 63040 Lockport Place, Lorton, VA 22079 Fax (for orders): (702) 920-8826 Tel: (703) 550-1994 Fax: (703) 354-9047 http://www.jandcphotography.com http://www.diversified-equipment.com sales@jandcphotography .com (Used densitometers) (Ekeand Classic film) ES Eseco Speedmaster. One Eseco Road, Cushing, PM Photomark. 2202 E. McDowell, Phoenix, AZ OK 74023-9912 85006 Tel: (800) 331-5904 Fax: (918) 225-1284 Tel: (800) 777-6627 Fax: (602) 273-0928 [email protected] http://www.photomark.com GM Gretag-Macbeth VCS View Camera Store. P.O. Box 19450, Fountain Tel: (800) 622-2384 Hills, AZ 85269 http://www.gretagmacbeth.com Tel: (480) 767-7105 Fax: (480) 767-7106 XR X-RITE http://www.viewcamerastore.com Tel: (800) 292-4435 [email protected] http://www.xrite.com (Also a source for large format film, printing frames, cameras, and densitometers) DIGITALSERVICES LABORATORYEou I PMENT AG LIZARDTECH Tel: (206) 902-2500 CLS Chem Lab Supplies. 1060 Ortega Way, Unit http://www.lizardtech.com “C”, Placentia, CA 92670 (Genuine Fractals interpolation and compression Tel: (714) 630-7902 Fax: (714) 630-3553 software) http://www.chemlab.com CG Copygraphics (Peter Ellzey). 314 Read St., Santa CPI Calumet Photographic. 890 Supreme Dr., Fe, NM 87501 Bensonville, IL 60106 Tel: (505) 988-1438 Tel: (800) 225-8638 Fax: (800) 828-5539 http://www.creativepro.com/outputresource/ http://www.calumetphoto.com home11 643.html ESc Edniund Scientifics. 101 E. Glouster Pike, (Digital scans and imagesetter negatives) Barrington, NJ 08007 EC Evercolor. 70 Webster St., Worcester, MA Tel: (800) 728-6999 Fax: (609) 547-3292 01603 [email protected] Tel: (508) 757-2216 or (800) 533-5050 GAS Graphic Arts Supermarket. 9701 Canoga Ave., Fax: (508) 757-2216 Chatsworth, CA 91311 http://www.treeo.com/out-optdevercolor.htm1 Tel: (818) 997-7771 or (818) 882-0168 light@evercolor .com http://www.magicyellow.com PW Photographic Works. 3550E. GrantRoad,Tucson, (Stouffer’s Step Tablets) AZ 85716 SL Slosher by John Sexton Tel: (520) 327-7291 http://www.photo.net/bboard/q-and-a-fetch- http://www.photographicworks.com msg?msg-id=003q8Q (Digital scans) TS Tri-Ess Sciences, Inc. 1020 W. Chestnut St., RA RASTUS Burbank, CA 91506 http://www.telegraphics.com.au/sw/info/ Tel: (800) 274-6910 rastus.htm1 http://www.tri-esssciences.com (A plug-in for Adobe Photoshop that creates (Almost everything for the alchemist) stochastically screened bitmaps; available for VRW VRW Science Products. P.O. Box 1002, Mac and PC) S. Plainfield, NJ 07080 Tel: (800) 932-5000 Fax: (908) 757-0313 http://www.vrwsp.com (Hygrometers) 222 SOURCES

PAPER UNITS AR Aristo Grid Lamp Products. 35 Lumber Rd., MA Martin Axon Tel: 203-245-7674 Roslyn, NY 11576 Tel: (516) 484-6141 Fax: (516) 484-6992 ASW Art Supply Warehouse. 5325 Departure Dr., http://www.aristogrid.com North Raleigh, NC 27616-1835 Bostick & Sullivan. Box 16639, 1541 Center Dr., Tel: (800) 995-6778 Fax: (919) 878-5075 BS Santa Fe, NM 87505 http://www.aswexpress.com Tel: (505) 474-0890 Fax: (505) 474-2857 [email protected] http://www. bostick-sullivan.com DS Daniel Smith. 4130 First Avenue, S., Seattle, Edwards Engineering. 5304 Arrowhead Dr., WA 98124-5568 EE Lago Vista, TX 78645-5803 Tel: (800) 426-6740 Fax: (800) 238-4065 Tel and Fax: (512) 267-4274 [email protected] http://www.eepjon.com NYC New York Central Art Supply. 62 Third Ave., (Also print dryers) New York, NY 10003 NuArc Company, Inc. 6200 W. Howard St., Tel: (800) 950-6111 Fax: (212) 477-0400 NA http://www .nycentral.com Niles, IL 60714 Tel: (800) 962-8883 Fax: (847) 967-9664 PT Paper Technologies, Inc. 6333 Chalet Dr., Commerce, CA 90040 http://www.mrprint.com/nuarc/default.asp Olec http://www.olec.com Tel: (562) 928-5600 Fax: (562) 927-6100 Psoralight Corp. 2806 William Puller Dr., http://www.papertech.com PS Stationery Store Columbia, SC 29205 ss Tel: (800) 331-3534 Fax: (803) 748-9985 SK Stephen Kinsella, Inc. P.O. Box 32420, Olivette, MO 63132 (Solar Specs) Tel: (800) 445-8865 Fax: (314) 991-8090 TR Twinrocker. 100 East Third St., P.O. Box 413, METALHALIDE FIXTURES AND LAMPS Brookstone, IN 47923 http://www.grainger.com/Grainger/start.jsp Tel: (800) 757-8946 Fax: (765) 563-8946 http://www. twinrocker.com http://www. bulbman.com [email protected] http://www.olec.com/graphicarts/OLEC- SpectramatchTM-Lampslolec-spectramatchtm- lamps.htm1 uv LIGHT SOURCES TUBES AND BALLAST RuBY LITH~ http://www.aquadirect.com/lighting/flourescent.html UL Mister Art: Ulano Masking Films http://www.americanlight.com/americanlight/home.htm Tel: (866) 762-7811 http://www.topbulb.com/default.asp http://www .misterart.com http://www.fullspectrumsolutions.com/UltraLux- Ballast.htm http://www.afforda blelighting.com/blowout.html http://www.uriworld.com/PRODUCTS/mlam.htm http://www.hamiltontechnology.com/shop http://www .bulbman.com RIMINI. ITAI~1996 12 x LO lNck PriPd 224 BIBLIOGRAPHY

HISTORIC CHEMISTRY

Abney, William Platiiiotype: Its Preparation and Anchell, Stephen G. The Darkroom Cookbook. Boston: Manipulation. London: Sampson, Low Marston, Focal Press, 1994. 1895. Bunting, Roger K. The Chemistry of Photography. Anderson, Paul L. Technique of Gum-Platinum: Normal, IL: Photoglass Press, 1987. (Available from The Technique of Pictorial Photography. New York: www.photoglass. coin ) J.B. Lipponcott, 1939. Rempel, Siegfried, and Rempel, Wolfgang. Health Newhall, Beaumont. The History of Photography. Hazards for Photographers. New York: Lyons and New York: Museum of Modern Art, 1982. Burford, 1992. Pizzighelli, Captain, and Hubl, Baron A. Platinotype. London: Harrison and Sons, 1886. Reprinted from The Photographic ]ourrial. 1883, DIGITAL pp. 5-59. Steiglitz, Alfred. Platinum Printing: The Modern Way Blatner, David, and Fraser, Bruce. Real World in Picture Making. Rochester, NY: Eastman Kodak, Photoshop CS, 6th Ed. Peachpit Press, 2004. 1905. Burkholder, Dan. Making Digital Negatives for Contact Printing. San Antonio, TX: Bladed Iris Press, 1998. (Available from tuzuw.cinnburkholder.com) CURRENT Fokos, David. www.wovkingpictures.com

Arnow, Jan. Handbook of Alternative Photographic Processes. New York: Van Nostrand Reinhold, 1982. GENERAL Crawford, William. The Keepers of the Light. New York: Morgan and Morgan, 1979. Davis, Phil. Photography, 7th Ed. Dubuque, WI: Brown Farber, Richard. Historic Photographic Process. and Benchmark, 1995. New York: Allworth Press, 1998. Edwards, Betty. Drawing on the Right Side of the Brain. James, Christopher. The Book of Alternative Los Angeles: J.P. Tarcher, 1979. Photographic Processes. New York: Delmar, 200 1. Kodak. Building a Home Darkroom. Kodak Publication Malde, Pradip, and Ware, Michael. The Ammonium KW-14. New York: Eastman Kodak, 1996. System: A Contemporary Method for Making Schaefer, John P., ed. An Ansel Adam Guide. Basic Platinum and Palladium Prints. http://mikeware. Techniques of Photography, Book Two. Boston: demon.co.uk Little, Brown, 1998. Nadeau, Luis. History and Practice of Platinum Simmons, Steve. Using the View Camera. New York: Printing. New Brunswick, Canada: Atelier Luis Amphoto, 1992. Nadeau, 1994. Stroebel, Leslie. View Camera Technique, 6th Ed. Rexroth, Nancy. The Platinotype 1977. Condon, MT: Boston: Focal Press, 1993. Formulary Press, 1977. (Available from Photograph- ers Formulary.) Shellea, Thomas J. Instruction Manual for the S ENSITOM FTRY Platinum Printing Process. Philadelphia: Thomas J. Shellea, 1982. (Available from Photographers’ Adams, Ansel. The Negative. Book 2. Boston: Little, Formulary) Brown, 1981. Sullivan, Richard, and Weese, Carl. The New Platinum Davis, Phil. Beyond the Zone System, 4th Ed. Boston: Print. Santa Fe, NM: Working Picture Press, 1998. Focal Press, 1998. (Available from Bostick Sullivan: www.bostick- Kodak. Professional Black and White Films. Kodak sullivan.coni) Publication F-5. New York: Eastman Kodak, 1998. Bibboqnnpky 225

Todd, Hollis N., and Richard D. Zakia. Photo- Hunter, Darth. Paper Making: The History and Tech- graphic Sensitometry. New York: Morgan & Morgan, nique ofan Ancient Craft. New York: Dover, 1974. 1969.

PYRO PAPER Hutchings, Gordon. The Book of Pyro. (1991) Airey, Theresa. Creative Photo Printmaking. New York: Available from: Gordon Hutchings, P.O. Box 2324, Amphoto, 1996. Granite Bay, CA 95746. Thispageintentionallyleftblank Acidification, 47 Average gradient, 17, 19, 22, 114 BTZS tubes, 1SSn, 156-157 Adams, Ansel, 16, 19, 120, 150, Axon, Martin, 44 Buffering solutions, 36 182, 183 Burkholder, Dan, 188 Advanced technique, 91-103 Ballast, 205 “black plague” cure, 100-101 Ballasted HID lamps, 204-205, Calibration, 63-73 double coating, 97 208 contrast control technique, drying of the coating, 97-99 Banquet cameras, 152-153 68-72 final print preparation, 99-100 Base + fog (BSF), 17, 18, 114 dichromate method, 73 glycerin, 97 Basis size, 42 light source, 64-66 humidification, 93-95 Basis weight, 42 printing with digital image hue, 95-96 Bergger 200 BPF, 161 negatives, 194-199 masking negatives, 92 Bergger BFP200, response to pyro, ratio method, 72-73 negative handlinghtorage, 103 181, 182, 182n standard negative contrast presentation, 101 Bergger COT 320, 42, 45 ranges, 73 working light, 92 Berkeley’s formula, 146-147 supplies, 66-67 Albumin, 93 Beyond the Zone System (1998), time/distance technique, 68 Alcohol, polyvinyl, 95 13, 21, 70, 112, 156, 15611, Calumet Photo, Inc., 8 Alum, 30 157 Cameras Ammonium citrate, 31, 33 Bienfang Graphics 360, 42, 44-45 banquet, 152-153 developing and clearing with, Black size of, 152-153 85,216 convincing, 21, 70 view, 151, 152, 153 print hue and, 96 streaking, 107 Chalky prints, 106 Anderson, Paul, 33 Black defects, 99-100 Chemicals, 27-38 Anemic prints, 106 Black light blue (BLB) tubes, 205, clearing agents, 31, 34-36 ANSI (American National 206 coating solutions, 30, 31-33 Standard Institute), 113, Black light (BL) tubes, 205 developers, 3 1, 33-34 1221-1 “Black plague”, 217 measurement units, 29 AQUA tubes, 205 “Black plague” cure, 100 monochromatic film Arches Cover, 43, 47 Black spots, 107 developing agents, Arches Platine, 40,42,43, 44, 213 Blamer, David, 190 29 double coating, 97 Bloom gelatin, 30 MSDS and, 28-29 humidified, 94 The Book ofPyro (1991), 182 oxidizing agents, 30-3 1 Arentz, Dick, 35,42,45, 188, 195, Brush development, 97 paper sizing, 30 197, 212 Brushes, 95 purity of, 30 ASA (American Standards coating, 79-81, 83 sources of, 38 Association), 17 Richeson, 10 toners, 36-38

227 Chemistry, 145-148 Contact printing frames, 11-12 table-model, 14 Berkeley’s formula, 146-147 Contrast, 20 transmission, 17, 19 clearing, 148 adjusting, 87-90 visual comparison, 66, 87-88 oxidation, 146, 147 negative, 18-24 Density, negative contrast versus, oxidation-reduction reaction Contrast control, 214 18-24 (redox), 146 calibration, 68-72 Density range (DR), 16, 17, 19-20 oxidizers, 147 combining ratio and Na2 digital negatives, 186-187 palladium printing with Na2, methods, 58-59, 60 film curves and, 113, 114 147-148 dichromate method, 60-6 1 Developers, 3 1, 33-34 reduction, 146, 147 methods of, 53-61 film combinations with, Chlorates, 3 1 percentage method, 58, 60 159-172 Chlorine, 100 platinudpalladium curves and, filtering of, 34 Circle of confusion, 25 115-118 formulas, 33 Citric acid, 35, 36 print curves and, 129 metal ions, 96 Clearing, 85-86 ratio method, 54-56 PH, 34 chemistry of, 148 serial dilution method, 57-58 potassium oxalate, 8 technique, 216 sodium chloroplatinate, 56-58 reuse of, 96 test strips, 78 Contrast Control in Iron Based temperature controls and, 34, Clearing agents, 31, 34-36, 41 Printing Processes (2001), 95-96 Clearprint vellum, 213 56, 14711 Development, 85-86 Clinical print, 142, 150 Contrast index (CI), 17 average gradient and, 22 Coating, 83-84 Contrast mixtures brush, 97 drying of, 97-99 digital negatives and, 195 effective film speed and, 22 papers for double coating, 43 speed changes produced by, glycerin and, 97 papers for single coating, 42 130, 133-134 paper toe and, 124 technique, 215-216 Convincing black, 21, 70 pyro, 182-184 uneven, 106 Corrected speed point, 134, 135, shadow density and, 19 Coating area, 8-9, 10 139 technique, 216 Coating brushes, 79 Crane’s Kid Finish, 42, 45 test strips, 78 coating rods versus, 83 Crane’s Natural Crest White zone system versus SBR, 21 technique, 79-81 Wove, 42, 43, 45-46, 46n Dichromate method Coating rods, 82 contrast control and, 67 calibration with, 73 coating brushes versus, 83 humidified, 94 contrast control, 60-61 technique, 82-83 Crane’s Platinotype, 42, 43, contrast mixtures for, 133 Coating solutions, 30, 31-33 45-46, 46n, 213 Dichromates, 3 1 filtering, 84 contrast control and, 67 Dick Arentz Kit, 38 metal salts, 32-33 humidified, 94 Digital 21-Step Tablet, 186, 200 metal utensils and, 33 Crocein Scarlet, 24, 99 Digital imaging, 185-202 restrainers, 32 Crown glass, 208 calibration for Pt/Pd printing, sensitizers, 31-32 194-199 Color density range control, 186, Darkroom Cookbook, 155 glossary, 186 193 Davis, Phil, 13, 60, 107, 112, 156, image file, 190-191 Color density range palette, 186, 15611, 157, 160, 162, 188 imagesetter negatives, 192 195-196 Daylight plastic tanks, 157 in-camera negatives versus, Commercial plate burners, 13 Defects 18 7-1 8 8 Compression of brightness ranges, black, 99-100 inkjet negatives, 192-194 20-21 white, 100 making a digital negative, Computer-generated negatives, Densitometers, 9, 13-14 199-201 in-camera negatives versus, hand-held, 14 making a PtRd print, 200-201 150-1 5 1 professional models, 14 materials list, 188 Conner, Lois, 44 pyro negatives and, 178-1 80 pixels versus dots, 188-189 Contact hazard, 28 reflective, 201-1,65 tones, 189 Dilute acids, 35 Exposure range (ER). Flammability hazard, 28 Distilled water, 30 See exposure scale (ES). Flashlight test, 153n Dmax, 112 Exposure scale (ES), 16, 65 Flattening, 217 double coating and, 97 definition of, 17 Flocculation, 3 1, 40, 54-55 paper curves and, 112, 115 paper curves and, 113 Fluorescent lights, 13 paper humidification and, 94 UV light sources and, 208 choosing print-to-light distance shadow values and, 129, 129n Eye protection, 9, 10 with, 64 Dmin, 112 exposure and use of, 8Sn film curves and, 112, 114 Fabriano Artistico, 43, 47, 93, 94 Fluorescent tube bank, 205 paper curves and, 112 Fabriairo Artistico Extra White, Fog, 146, 147 Dodging and burning, 85 213, 214 causes of, 106 Dots, pixels versus, 188-1 89 Fabriano Classic0 CP, 43, 47, 48 controlling, 32 Double coating, 43, 48, 97 Fabriano Murillo, 42, 43, 46, 48 hydrogen peroxide and, 95 Droppers, serial dilution method Fabriano Perusia, 42, 46 platinum/palladium curves and, using, 57 Fabriano Uno HP, 43, 47 116, 117 Drum processing Ferric oxalate, 30, 3111, 31-32 versus stain, 107-108 filddeveloper combinations, humidification and, 94 Fokos, David, 188 162 hydrogen peroxide and, 95 Formaldehyde, 30 large negatives, 156 reduction of, 78, 146, 147 Framing, 101 Dry down, 87 Ferric oxalate ratio method, 54 Fraser, Bruce, 190, 191 Drying, 84-85 File capture, digital image, 190 Fresnel lens, 24 of coating, 97-99 File preparation, digital image, Full tonal range print, 142 of the final print, 99 190-191 Drying area, 9 Filling in, 217 Gamma (y), 17 Dry mounting, 101 Film Gamma infinity, 22, 57, 160 Duplicating negatives, 212-213 320 TXP, 161, 162, 171 G'impi, 42, 46 400T max, 160, 161, 166 Gelatin sizing, 95 Editions, 101 Bergger 200 BPF, 161 Gilpin, Laura, 4 EDTA (Ethylene diamine choosing, 160-1 62 Glass, 208-209 tetraacetic acid), 31, 34, 3.5, Classic 400, 162, 168, 172 Glasses, anti-actinic, 9, 10 3611, 148 Delta 100, 160, 161, 162, 163 Glycerin, 38, 97 Effective film speed (EFS), 17, developer combinations with, Gold chloride, 37, 96 22-24 159-172 Graininess, 24, 107 Efke 100 PL, 160-161, 162, 164 Efke 100, 160-161, 162, 164 Graining, chlorates and, 3 1 Efner, Howard, 30n, 564 147n, FP4 plus, 161, 162, 165, 169 Gram weight, 42 147- 148 HP5 plus, 161, 162, 167, 179 Guinness, Sir Alec, 151 Electronic ballasts, 205 organization of, 153-154 Ellzey, Peter, 212 response to pyro, 180-182 Hand-held densitometers, 14 Emerson, P.H., 151 Film curve, 19, 23 Handling, of negatives, 103 Emulsifiers, 95 platinum/palladium, 115 Harrison Film Changing Tent, Enyeart, Jim, 86 silver, 113-1 14 153n Equipment, digital imaging, 188 Film hangers, 157 Heated developer, 34 Etching, 99, 100, 217 Filtering Herbst, Bob, 2Sn, 1551-1, 173, 179, Evaluation coating solutions, 84 181 negative, 200-201 developer, 34 High-contrast negative process, 200 Final print, preparation of, 99-100 palladium curve, 120 Evans, Frederick, 151 Finishing platinudpalladium curve, Exposure, 18-1 9 etching, 217 115-116 digital negatives and, 195 filling in, 217 print curves, 138-139 negatives and, 85 flattening, 2 17 High intensity discharge (HID) technique, 216 spotting out, 217 lamps, 204-205,208 Exposure area, 9-10, 11 waxing, 217-218 High-key print, 142 Highlights Kodak 400Tmax, 160, 161, 166, Luminaire, 64, 204 IDmax and, 114 180-181 pyro and, 177 Kodak: Building a Home Magnetic ballasts, 205 Hue, 9Sn, 95-96 Darkroom, 8 Malde-Ware Method, 54, 93 Humidification, 93-95, 215 Kodak Professional: Masa, 42, 46 Humidity, in the laboratory, 92-93 Black-and- White Films Masking of negatives, 92 Hutchings, Gordon, 174, 182 (1998j, 157 Matcher Program', 121 Hydrochloric acid, 31, 35, 36, combining matcher files, 100,216n Laboratory 123-124, 125 Hydrogen peroxide, 31, 95, 147 coating area, 8-9, 19 palladium print, 122-123 Hydroquinone, 29 contact printing frames, 11-12 silver gelatin print, 121-122, Hygrometer, 8, 10 densitometers, 13-14 123 Hypo clearing agent, 35-36 drying and exposure area, 9-10, Materials 11-12 calibration, 66-67 IDmax, 70, 93-94, 112, 113 materials needed for, 10, 11 digital imaging, 188 film curves and, 112, 114, 115 relative humidity in, 92-93 laboratory, 10, 11 paper curves and, 112,113,115 ultraviolet light source, 12-13 masking negatives, 92 IDmin, 112n, 112-113 wet space, 8, 10 Material Safety Data Sheet film curves and, 112, 114, 115 Lamps, ballasted HID, 204-205, (MSDS), 28-29 paper curves and, 11211, 208 Matting, 101 112-1 13 Large negative, 149-157 Measurement units, 29 Ilford 100 Delta, 160, 161, 162, BTZS tubes and, 156-157 Melvin, Stuart, 212, 215 163 camera size and, 152 Mercuric chloride, 38 Ilford 125 FP4+, 161, 162, 165, film hangers, 157 Mercury vapor lights, 13, 204 169 in-camera versus computer- Metal halide lights, 13, 204-205 Ilford 400 HP5+, 161, 162, 167, generated, 150-151 Metal ions, in developer, 96 179, 181 organization of exposed film, Metal salts, 30, 32 Image densities, 112, 113 153-1 54 Metals, noble, 147 Image hue, 95-96 processing, 154-156 Metal utensils, 33 Image Perfect R, 101 ultra-large format, 152-153 Metol, 25, 29 Imagesetter negatives, 192 Lead oxalate, 38 Metric system, 29 creating, 199 Lenox ZOO, 42, 46 Millea, Tom, 92 density range, 195 Lens aperture, 18 Monochromatic film developing In-camera negatives, digital Lens flare, 17, 18, 114 agents, 29 negatives versus, 187-1 88 Light Mounting, 101 Inkjet negatives, 192-1 94 calibration, 64-66 Muriatic acid. See hydrochloric creating, 200 ultraviolet, 203-209 acid. printer settings, 193-1 94 working, 92 Mutmansky, Michael, 100, 100n IS0 (International Organization Lighting, presentation, 101 Mylar, 85 for Standardization), 17, Light integrators, 13, 67n 22-24 Lights Na2 method. See sodium fluorescent, 13, 205 chloroplatinate method. J & C 400 Classic, 162, 168, 172 mercury vapor, 13 Nanometer, 12 JOBOR processor, 156, 1.5611 metal halide, 13 The Negative (1981j, 182 advantages of, 154-155 Light table, 9 Negative contrast, 18 filddeveloper combinations, Linters, 40 negative density versus, 18-24 162, 163 Liquitex acrylic sizing medium, 95 selenium toning and, 25 Logarithmic system, 17-1 8 toner and, 36 King, Sandy, 12, 188, 203, 205 Low-contrast negative Negatives, 15-25, 212. See also Klimek, Stan, 47, 211 platinudpalladium curve, sensitometry, photographic. Knox gelatin, 30 116-1 18 average gradient and, 22 Kodak 320 TXP, 161, 162, 171 print curves, 138-139 circle of confusion, 25 computer-generated, 150, 15 1 PdPd comparison, 5-6 process adjustment curve and, contrast versus density, 18-24 solarization and, 108 198 density range, 19-20, 195-1 96 Palladium chloride, 32, 33 sharpening with, 190 density values, 135-139 Palladium curves, 118-121 Pinholes, 24-25, 107 development, 19, 20-21, 124 high-contrast negative, 120 Pipettes, serial dilution method duplicating, 212-213 Na2 method, 119 using, 58 effective film speed and, normal contrast negative, 119 Pixels, dots versus, 188-1 89 22-24 previsualization and, 120 Pizzighelli, Giuseppi, 4 exposing, 18-1 9, 20-21 ratio method, 118-1 19 Plate burners, 13, 206 graininess, 24 Palladium printing Plating, 93 handling of, 103 matching film to paper, Platinotype papers, 40-41 high-contrast, 115-116, 120, 122-123 acidification, 43, 47-48 138-1 39 ratio method, 72-73 characteristics of, 41-48 imagesetter, 192, 195, 199 with sodium chloroplatinate double coating, 43, 48 inadequate contrast in, 118 (Na2), 147-148 single coating, 42, 44-47 in-camera versus digital, Paper, 39-48, 213 Platinum 18 7-1 8 8 acidification, 43, 47-48 combinations of palladium and, inkjet, 192-194, 200 characteristics of, 41-48 96 low-contrast, 116-1 18, double coating, 43, 48 contrast control and, 55 139-141 humidity and, 93-95 Platinudpalladium curve, masking of, 92 platinotype, 40-41 114-115 overexposed, 20 platinum, 4 family of, 118, 119 pinholes, 24-25, 107 print curves and, 139, 141 high-contrast negative, platinudpalladium prints, 115 silver gelatin, 4-5, 20-22 115-116 processing large, 154-157 single coating, 42, 44-47 inadequate contrast negative, pyro, 25, 178-180, 183-184 sizing of, 30 118 scratches, 24-25 variations in, 41 low-contrast negative, 116-1 18 selenium toning, 25 weight measurements, 42 Platinudpalladium printing sharpness, 24 Paper curves adjusting contrast, 87-90 silver paper, 113-1 14 platinurdpalladium curve, algorithm for, 77 storage of, 103 114-115 calibration for digital negatives, subject brightness range (SBR), silver curve, 112-1 14 194-199 2 1-24 silver versus Pt/Pd, 112 coating, 83-84 underexposed, 20 using portions of, 141-144 coating brushes, 79-81, 83 Nelson, Mark, 151, 185, 18511, Paper testing techniques, coating rods, 82-83 201 42-44 contrast control, 53-61, 214 Noble metals, 147 Paper toe, 113, 122n, 124 developing and clearing, 85-86 NuArc, 13, 13n Penn, Irving, 4 dodging and burning, 85 Numbering, of editions, 101 Percentage method, contrast dry down, 87 control, 58, 60 drying, 84-85 Opacity range, 20 PerfectGlassm, 101 duplicating, 212-213 Opaline, 42, 46 PH etching, 99, 100 Overexposure, 23 of developer, 34 exposure, 85 Oxalic acid, 35, 36, 43 of paper, 42, 43 finishing, 217-218 Oxidation, 31, 146, 147 of prints, 36 first print, 49-52 Oxidizers, 30-31, 32, 147 Phosphoric acid, 35, 3511, 36 laboratory set-up, 7-14 Photographic sensiometry. negatives, 212 Palladium See sensiometry, paper, 213 combinations of platinum and, photographic. photographic sensiometry and, 96 Photoshop"", 151, 15111, 191 16 contrast control and, 55 duplicating negatives with, 212 printing history of, 4 print curves and, 140, 142 imagesetter negatives and, 192 PdPd comparison, 5-6 Platinundpalladium printing Prints Pyro negative, 25 (continued) anemic, 106 Pt/Pd solution, 213-214 assessments of, 52 Quad tap, 204 silver process compared with, black spots on, 107 4-5 chalky, 106 Rapid Selenium Toner, 36 spotting, 99-1 00 clinical, 142, 150 Ratio method, 64 technique, 2 14-2 16 evaluating, 200-201 calibration and, 72-73 test strip, 76-78 full tonal range, 142 contrast control, 54-56 utensils for, 76 high-key, 142 contrast mixtures for, 133 Plotter Program'"', 112, 121, 156, hue, 95-96 palladium curves and, 160 pH of, 36 118-119 Plus percent, 58 presentation of, 101 platinundpalladium curves and, Point light source, choosing sun print, 50-52 117 print-to-light distance with, toning, 36-38 print curves using, 129-130, 64 Print speed 131 Polyvinyl alcohol, 95 contrast control and, 129 Reactivity hazard, 28 Posterization, 189 contrast mixtures and, 130, Real World Adobe Photoshop CS Potassium chlorate, 31, 32 133-1 34 (2004), 190 Potassium chloroplatinite, 32, 146 pyro and, 177 Ream, 42 Potassium dichromate, 3 1, 32 UV light sources and, 208 Redox reaction, 146 Potassium oxalate, 31, 6711, 216 Print-to-light distance, choosing, 64 Reduction, 146, 147 developing solutions with, 33 Problems, 105-108 Reflection opacity ratio, 20 EDTA and, 35 black spots, 107 Reflective densitometer, 2011, 65 print hue and, 96 chalky or anemic prints, 106 Reflective density, 64, 65-66, temperature of, 8n, 34 fog versus stain, 107-108 112-1 13 PowerDial", 156, 161 graininess, 107 Reflective density range, 20, 21 Power J & C Classic, 161 solarization with palladium, Relative humidity, 92-93 Precision Digital Negatives for 108 Restrainers, 30, 32, 147 Alternative Photographic streaking blacks, 107 Richardson, John, 212 Processes (2004), 186n, 193, uneven coating, 106 Richeson brush, 10 20 1 Process adjustment curve, 186, Rising Drawing Bristol, 41, 42, 46 Presentation, 101 187, 196-199 Rising Gallery 100, 43, 48 Previsualization, 1711, 120 Process evaluation, 200 Rives BFK, 43, 47, 48, 213 Print curves, 127-144 Processing Rods, coating, 82-83 algorithm use, 134-135 large negatives, 154-157 Rotary development analyzing, 129-130 pyro, 182-1 84 advantages of, 154-155 contrast control, effects of, 129 Psoralight Corporation, 12n filddeveloper combinations, Na2 method, 130, 132, 133 PtIPd printing. See platinum/ 162-1 63 negative density values and, palladium printing. Rubylith", 64, 78, 85, 92, 215 135-1 39 Puddle Pusher R, 82 shadow values, 128-129 Purity, of chemicals, 30 Sabattier effect, 93 speed changes, 130, 133-134 Pyrogallol (pyro), 25,29, 173-184 Safelight, 92 speed point, 141 advantages of, 176-177 Schreiber, Keith, 35, 39, 42, 44, using portions of, 142-144 characteristics of, 174, 176 45, 47, 57n, 83, 84, 97, 102, Printers densitometers for reading 162 building, 205-206 negatives, 178-180 Scratches, 24-25 settings for inkjet negatives, disadvantages of, 177-178 Selenium toner, 25, 36 193-194 film response to, 180-1 82 Sensitizer Printing formulas, 182 contrast control and, 30 digital imaging, 200-201 processing, 182-1 84 reduction of metals and, 146 first print, 49-52 sensitometric effects of, 174, sizing medium in, 95 pyro, 173-1 84 175 solutions, 31-32 Sensitometry, photographic, 16 Sodium citrate, 31, 33 Stouffer TP, 65, 67, 6711 definitions, 17 Sodium dichromate, 31, 32 tonal palette, 186 density range for negatives, 18 Sodium hexachloroplatinite, 30 Step wedge, 186 film and paper curves, 109-125 Sodium sulfite, 34, 35 Stieglitz, Alfred, 97 logarithmic system, 17-1 8 Sodium tetrachloropalladate, 32, Stir-and-heat plate, 8n, 9, 10 negative contrast versus density, 33, 146 Stochastic screening, 192 18-24 Solarization Stonehenge Rising, 213, 214 print curves, 127-144 humidification and, 93, 94 stop, 18, 20 transmission densities, 17 palladium and, 6, 108 Storage, of negatives, 103 Serial dilution method, contrast prevention of, 93 Stouffer step tablet, 174, 175 control, 57-58 Solar Specs“, 1211, 20411 Stouffer TP step tablet, 65, 67, 67n Shadow density, 18-19. See also Solution Strand, Paul, 151 print curves. buffering, 36 Strathmore Series 500 Bristol, 42, effective film speed and, 22 coating, 30, 31-33, 84 46 film curves and, 114 PtIPd, 213 Streaking blacks, 107 Shadow values, print curves and, Somerset, 213 Subject brightness range (SBR), 17 128-129 Specialty glasses, 208-209 compression of, 20, 21 Sharpening, digital images, 190, Spectral density, 174 development for, 21-24 191 Speed effective film speed and, 22-24 Sharpness, 24, 208 contrast control and, 129 film curves and, 113-1 14 Shoulder, of paper curves, 113 contrast mixtures and, 130, high, 22 Silver gelatin prints, 20, 22 133-1 34 low, 21-22 Silver process pyro and, 177 zone system development film curve, 113-1 14 UV light sources and, 208 versus, 21 matching film to paper, Speed bar, 135-138, 143, 143n Subject-luminance ratio, 17, 20 121-122, 123 Speed index, of paper, 42, 43 Sulfites, 34, 36n paper curve, 112-1 13 Speed point, 129, 135, 141 Sullivan, Kevin, 100n previsualization and, 120 Spot meter, 1711 Sullivan, Richard, 31, 56, 96, 97, Pt/Pd comparison with, 4-5 Spotone”, 2 17 1OOn Simili Japon, double coating, 97 Spotting, 99-100, 217 Sullivan’s cold water developer, 33 Sizing Stain, versus fog, 107-108 Sullivan’s gold tone, 37 acid paper and, 40 Standard 21-Step Test Tablet, Sunlight, 12, 204 image hue and, 95 186,200 Sun prints, 50-52 technique, 214 Standard Contrast Range Chart, Super actinic (SA) tubes, 205, use in sensitizers, 95 55-56 207-20 8 Skies, coating and, 81 Standard density color, 196 Supplies Slosher, 156 Standard Negative Contrast calibration, 66-67 Smith, Norma, 212 Ranges, 73 digital imaging, 188 Smooth gradient test tablet, 186 Starch sizing, 95 laboratory, 10, 11 Socorro Platinum, 47 Starfire, 208-209 masking negatives, 92 Sodium acetate, 36, 87 Starrenburg, Bruce, 188 Swiss Opaline Parchment, 42, 46 Sodium carbonate, 36, 87 Step tablet, 34, 47 Sodium chloroplatinate (Na2), 5n, calibration with, 64-65 Tank development, 157 31, 32, 43n color density range palette, Target log density, 197, 198 Sodium chloroplatinate (Na2) 186 Technique method contrast adjustment using, advanced, 91-103 contrast control, 56-58, 68, 70, 87-90 buffering, 36 71, 214 Digital 21-Step Test Tablet, 186 coating, 30, 31-33, 84, palladium printing with, smooth gradient test tablet, 186 215-216 147- 148 Standard 21-Step Test Tablet, coating, with brushes, 79-81 print curves using, 130,132,133 186, 200 coating, with rods, 82-83 time/distance technique, 68 Stouffer, 174, 175 developing and clearing, 216 Technique (continued) Transmission densitometer, 17, 19 Vacuum easel, 11, 12 exposing, 216 Tray development Vacuum frames, 208 humidifying, 215 filddeveloper combinations, Van Gelder Simili Japon, 42, 43, paper testing, 42-44 162-163 47,48 sizing, 214 large negatives, 156 Vellum, 41, 41n time/distance, 68 pyro and, 183 View cameras, 151, 152, 153 toning, 96-96 Tri-X Pan Profession Film (TXT), Visual comparison densitometer, Temperature, developer and, 8n, 23,2311, 25 17, 66, 87-88 34, 95-96 Tubes, fluorescent, 205, 206 Test strips Tween 20'", 84, 97 Wang, Sam, 188 coating, 76-78 Twinrocker Watercolor, 43, 48 Water, distilled, 30 developing and clearing, 78 Twinrocker White Feather Waxing, 217-218 making of, 67 Watercolor Deckle, 48 Weese, Carl, 97 Threshold, 18 Weight, paper, 42 Tice, George, 4 Ultra-large format cameras, Weston, Edward, 182 Time/distance A+B method, 152-153 Wet space, 8, 10 calibration, 68 Ultraviolet (W)light, 12-13, White defects, 100 Toe, paper curves, 113 203-209 White, Minor, 21, 70, 120 Tonal palette, 186, 196 ballasted HID lamps, 204-205 Willis, William, 4, 145 adjusting image file using, 199 building a UV printer, 205-206 Wimberley, John, 174, 182 process adjustment curve and, fluorescent tube bank, 205 Window glass, 208 197 plate-burners, 206 Working light, 92 Tone, 9511, 189 printing lights, 204 Toners, 36-38 pyro negatives, 178-179 X-Rite densitometers, 178-180 Toning, advanced technique, the sun, 204 96-96 testing, 206-207 Ziatype'" process, 5, 54, 93 Transmission densities, 17, 64, 65, UV blockers, 208-209 Zone system photography, 19, 20, 66. See also print curves. Underexposure, 23 120, 1201-1