How to trap using Adobe trapping technologies Table of Contents  Introduction ...... 4 What is trapping? ...... 5 Common problems ...... 6 How trapping solves these problems ...... 7 Common trapping situations ...... 8 Methods for avoiding register problems ...... 9

Trapping details Trapping gradients ...... 12 The sliding trap ...... 12 Metallic and spot colors ...... 13 Varnishes and non printing inks ...... 13 Images against gradients ...... 13 Images with complex backgrounds ...... 14 Images on images ...... 14 Rich trapping ...... 15 Keep-away trapping ...... 15 Vector-to-Continuous-tone trapping ...... 16 Text over Continuous-tone images ...... 17 Trapping clipping paths ...... 18 Where thin strokes need special handling ...... 19

Adobe technology solves trapping problems Trap settings ...... 22 Trap styles ...... 23 Corner mitering ...... 23

Adobe trapping technologies and how to use them Adobe trapping in common workflows ...... 26 Adobe in-RIP trapping ...... 27 Adobe PDF Trapper ...... 28 Adobe, the Adobe logo, AdobePS, Manager, Acrobat, Acrobat Exchange, ATM, Distiller, Adobe InDesign® ...... 30 Extreme, FrameMaker, Illustrator, InDesign, PageMaker, Photoshop, PostScript, and PostScript 3 are InProduction® ...... 32 either registered trademarks or trademarks of Adobe Systems Inc., in the United States and/or other Adobe PageMaker® ...... 34 countries. Microsoft, Windows, and Windows NT are either registered trademarks or trademarks of Microsoft Corporation in the United States and/or other countries. Apple, , and TrueType are trademarks of Apple Computer, Inc., registered in the United States and other countries. UNIX is Adobe technology partners a trademark of the Open Group. All other trademarks are the property of their respective owners. Adobe in-RIP trapping partners ...... 38 Copyright 2002 Adobe Systems Incorporated. All rights reserved. Printed in the USA. BC2730 4/02 Introduction What is trapping? A problem that has been around since Gutenberg’s time When good presses and good paper go bad

In the 16th century, Johann Gutenberg Fortunately, most of Gutenberg’s The sophistication of printing has also Trapping is a prepress procedure that out of register, the edges of touching ordinarily sophisticated—they must had press problems galore! He printed printing was done in a single color– improved, as has the need to prevent introduces areas of color into color colors either overlap, creating an resolve every possible press register from metal type of his own making most of the color ornamentation in press register problems before they separations. When printed, these areas unattractive color intersection, or they error for any combination of colors onto animal skin called vellum. The his famous 42-line bible was added by occur. This is a process of building better obscure potential register errors. spread apart, creating a partial outline and printing elements. problems of press register were not artisans after printing. If Gutenberg presses and processes, and by improving of white paper showing through (See unknown to the famous printer. had decided to print his breathtakingly preventive elements in the artwork These errors are usually caused by the the illustration on the facing page). beautiful bibles in multiple colors, he we prepare for printing. One of these paper shifting or changing shape while If the vellum was too dry, it wouldn’t wouldn’t have been able to keep the preventive techniques is the process of it is printed, or by presses or plates Compensating for register error hold Gutenberg’s secretly formulated colors in register or achieve the quality trapping jobs in advance of printing. that are out of register. As a result, the involves corrective trapping elements ink. So he would gently dampen the of artistry he sought. colors print incorrectly. which can be surprisingly complex, vellum just prior to printing on it. for artwork can have many different Gutenberg avoided trapping Excessive register error is evident colors and types of color intersections. As the paper dried, it changed shape, His solution to press register error when the colors in an image appear causing slight imperfections in was to avoid situations where color blurry, but typical register error is The methods for creating corrective his books. could go out of register. As printing much more subtle. When colors go trapping elements must be extra- has become more precise, so has the need to control paper and press conditions, and the precision of placing one color atop another when printing multiple colors.

How trapping solves register problems The background color is set to 100% . The background color is set to 100% magenta.

The intended color of the letter is set to 100% . The intended color of the letter is 100% cyan.

If the press goes out of register, the cyan letter shifts A trapping element added to the illustration spreads the to the upper-left, creating a partial outline of lighter color (cyan) into the background. In this example, white paper showing through the trapping element is cyan. The thickness of this element … and a partial dark blue outline appears where is typically very small, but it is adequate to cover any the cyan and magenta overprint. anticipated press register error.

(The size of the register error and trapping correction are exaggerated in these illustrations to show the effects of misregister and trapping.)

4 5 Common printing problems How trapping solves these problems Production processes contribute to register error When done correctly, trapping does its job behind the scenes

Occasionally a press produces printing Paper bounce can cause problems Sometimes the pressure of deadlines Trapping introduces corrective sophisticated and surprisingly subtle. page description while vector-based that is out of register. Reasons can Paper that prints out of register is often cause press operators to run their color elements to a printing job A properly generated element is the trapping provides speed and high- include poorly maintained machinery, caused by the sheet hitting the gripper machines too fast, increasing the In the process of trapping, new right color and shape. quality trap shaping. mishandled printing plates, mis- stop in the press, and bouncing slightly chance of register error. elements are added to the color managed printing data, poor raw backward before the gripper closes. separations. When printed, Today’s creative printing projects call Correcting errors shouldn’t materials, or human error. Press condition is also a cause of press these elements compensate for for trapping elements that are more create new problems In a multicolor press, the sheet is misregister. If machinery isn’t properly potential problems on the press. complex and trapping techniques that When trapping is done well, the new Paper can cause register error handed off from one press unit to the maintained, the press becomes a factor are superior to those used in the past. printing elements don’t show at all; Paper can cause register error if it next, introducing an opportunity for in poor register, creating trapping In general, the amount of error expected With gradients, superimposed images, they fix the problem and remain is manufactured incorrectly. If its paper bounce between each exchange. problems. in a quality printing job is no more than metallic inks, and extraordinary essentially invisible in the process. affinity to water isn’t controlled in If a press is set incorrectly, or if a press half of one halftone dot. Trapping combinations of artistic elements, production,* the paper can change is run too fast for optimum printing elements are usually generated to the trapping must be more capable Over-assertive trapping elements can size slightly on the press, causing conditions, register error occurs more same size, adding color components than ever before. Adobe trapping become visible and create more of a register error. often and more readily. that will cover or fill errors on press– technologies apply precise vector problem than the problem they were if they occur. analysis to all marking operations to meant to solve. combine the benefits of raster- and Trapping systems introduce micro- vector-based trapping. Raster-based scopic elements in ways that are both trapping produces accurate color and 1 2 3 4 EAT The -gold The black object object is lighter than is darker than its AT its surrounding color. surrounding color. A trapping element The trapping element JOE’S spreads into the is choked into the darker color. darker color.

The yellow-gold trapping element overprints the background color and prevents register error from appearing as a white gap. Register problems can manifest themselves in a variety of Example 3 shows the effect of white type reversed-out of ways. In example 1, the red is set to knock out the cyan. a rich black. If the press goes out of register, the letters are Simple trapping elements are called “spreads” and “chokes.” If the press goes out of register, the red overprints the compromised; small type can become illegible. Example In the example at left, the yellow-gold object spreads into cyan, creating a dark brown hairline on one edge and a 4 shows the relationship between cyan and yellow in a the black object to prevent register error. In the example on white hairline on the other. In example 2, the yellow text knock-out situation. If the press goes out of register, the right, the yellow background color is choked into the is designed to knock out the magenta. If the press goes out a white gap appears up at the top of the symbol, and a black object. In both cases the yellow-gold trapping element of register, the letters take on a brownish drop shadow. green halo appears at the bottom. would overprint, and it wouldn’t be visible as it is in these illustrations.

6 7 Common trapping situations Methods for avoiding register problems Why trapping is important A number of routes to a trap-free project

Colors that touch usually The four common process colors Designing around trapping Avoiding trapping requires care all potential register errors with a This technique has several advantages: require trapping in commercial printing are cyan, Projects designed to be printed Clever designers can avoid the perils relatively thick line of black ink. Design is easy, trapping concerns are Colors that touch create trapping magenta, yellow and black. These without trapping are made so that of press misregister by designing This technique is still used to avoid eliminated, and processing time risks if the press goes out of register. four colors can produce millions of colors don’t touch, or if they do, projects that don’t require trapping. register error. is reduced. Depending on the colors and their combined colors. Often the artwork they share a common palette. intensity, a trapping system will may require two or three of the One common method for avoiding Common color palettes When properly planned, common generate a new printing element process colors to be printed atop To avoid trapping, it is a relatively easy, register error is to design projects Another method to avoid register color palettes can be attractive, and they to compensate for potential or adjacent to one another. but jobs designed this way lack the where colors don’t meet or overlap. problems is to use color palettes that provide an acceptable but complex register error. benefits of a full-color printed project. This technique creates a serious contain a small percentage of the solution to press misregister risks. Even the finest printing constraint to design. other colors in a design. For example, Where similar colors touch, trapping needs trapping where yellow and cyan touch, a cyan- isn’t necessary, but colors that are Rarely does a job need no trapping “Comic book style” art looks like yellow trap element is needed, but printed by the different units of a at all. a comic book! with a common color palette. By are prone to print “Comic book style” represents a classic adding 20 percent yellow to the cyan out of register and are the targets Even today’s modern presses cannot method for avoiding register error. in a custom palette, trapping becomes for corrective trapping elements. hold perfect register—a small amount Since the 1930s, artists have used unnecessary, because the colors have of register error can occur in normal a method called black trap to cover the 20 percent yellow in common. printing.

ACME PAINT COMPANY ACME PAINT COMPANY

The illustration on the left uses solids and tints common color palettes is the limited number of process colors and has many opportunities of color choices available in the palette. This “Comic book style” uses a black outline to trap all color for register error. The illustration on the right is a complex solution to a problem that can be elements. When black overprints, it prevents register errors uses a palette where each color contains at solved more easily and effectively with Adobe from showing. This solution is perfect for some types of least 15% of the adjacent colors; it requires trapping technology. artwork, though inappropriate for more common illustrations no trapping. The challenge of working with and text.

8 9

Trapping details Trapping details Trapping details Gradients present real challenges for any trapping technology Novel color and image combinations

Gradients Gradients-on-gradients unique to Adobe trapping technology, Metallic and spot colors trapping technology, creates traps Images against gradients Gradients challenge any trapping A gradient against a solid color is and it significantly improves state-of- Curiously, some of the most celebrated between these inks based on supplied The capabilities of a sophisticated system because the colors and their reasonably easy to trap. Usually it is the-art trapping technology. trapping solutions in the graphic arts knowledge of the order in which the trapping system are put to the test values change within the art, and the trapped with a line of the unchanging industry cannot analyze and trap non- inks are printed. This process assures when an image is floated over a relationship between the gradient and color. But if two gradients overlap, the process colors successfully. that traps spread in the direction that gradient–or vice versa. A sophisticated its background changes continuously. challenge is much greater. The lighter retains the shape of the original design. trapping system will analyze the colors color will change as the gradients If a spot color or metallic color is on each side of the intersection at Before electronic prepress technologies interact. introduced into a design, it creates a Varnishes and non-printing inks every point and then create a trap color existed, this particular problem would special circumstance that challenges Some printing jobs include varnishes, that varies to accommodate the color have been insolvable, or it would have The sliding trap trapping technologies and causes most which may cover all or a portion of a changes. Adobe trapping technology been solved with crude techniques. Adobe trapping technologies use to fail. Many fully-automated processes page, or other transparent or special does just that, and it places the trap to With Adobe trapping technologies, a sophisticated trapping element A traditional trap, above, is abrupt, and calls default instead to a no-trap intersection inks that don’t need trapping, such straddle the edge smoothly or it places gradients can be trapped effectively, called a sliding trap to trap complex attention to itself. A sliding trap, below, is between the spot or metallic colors as those used for designating die the trap according to custom settings. easily, and successfully. gradients. This trapping element is much more subtle and effective. and other elements in the design. cuts. Adobe trapping technology allows such inks to be designated as If designs include opaque inks, transparent. It then ignores trans- like metallic inks, a fully capable parent colors when creating traps. trapping solution such as Adobe

Process Color Blend

Spot Color Blend

In the gradients shown here, the challenge is to trap two that follows the yellow gradient. This type of trap is colors where the value of each color changes continuously. exceptionally difficult, but Adobe trapping technologies The example on the left will elude most trapping systems– In the example on the right, the image is to be trapped into a In the upper example, four different gradients must handle these situations with ease. (The trap elements are trapping a process color gradient into a spot color gradient. process color gradient. Adobe trapping technologies handle be trapped against each other with dynamic trapping exaggerated in these illustrations.) Trapping complex images into gradient backgrounds poses one of both easily. elements. The lower example requires a gradient trap the greatest challenges to a trapping technology.

12 13 Trapping details Trapping details Some design elements need special trapping Rich black trapping

Images with complex Images on images This trapping element is determined A technique for printing black often ”Keep-away” trapping Adobe trapping systems create backgrounds Floating images atop other images by an analysis of the pixel values along includes creating a rich black or a A problem arises, however, when copy effective rich-black traps In the past, effective trapping would creates a surprisingly complex the intersection. Then the trapping super black–a–a combination of black is reversed out (also called knocked A sophisticated trapping solution have been nearly impossible when situation for a trapping technology. element is generated to prevent and a percentage of one or more of the out) of a rich black color. If the press is needed to create such keep-away overprinting a color photo on a complex With Adobe trapping technologies, press trouble without calling undue other process colors. or paper go slightly out of register, one traps in all possible circumstances, background. The common prepress it is now easy to do a better job. attention to itself. or more of the component colors can and Adobe trapping technology method would have been to knock the The trapping system analyzes the Rich “peek” out from behind the black. can generate such elements for any photo out of the background, and then intersections between the images, Placing tints of colors under black printing situation. print the photo in the knock-out. and creates a correctly colored trapping makes the black appear richer. The To avoid this problem, capable trapping element to prevent register error from tint and intensity of a rich black can systems create a keep-away trap,trap, With Adobe trapping technologies, showing on the printed sheet. be adjusted to suit the design or press where the artwork is reversed out of a photo can float over any combi- criteria. Putting tints of colors under the black at final size, while any nation of graphic elements. The black makes the black appear richer component colors are spread away necessary trapping elements prevent and can be more attractive in a from the knocked-out black. The unattractive intersections if the press project design. resulting knock-out is more tolerant goes out of register. of register error.

If artwork is reversed out of a rich black and the press “keep-away” trap (example on right), where colors other goes out of register, one or more of the component colors than the topmost color are printed away from the defining If a continuous-tone image floats over a complex into account, and the trap element created must can “peek” out of the reverse (example on left), affecting color. In this example the cyan is held back from the edge background, the challenge of trapping is com- be effective and subtle. (The trap elements are its appearance. The solution to rich-black trapping is the of the black. pounded. If an image overlays another image, exaggerated in these illustrations.) the situation is similar. Trapping elements must take both foreground color and tonal values

14 15 Trapping details Trapping details Vector-to-continuous-tone trapping Text over continuous-tone-images

Adobe trapping technology allows you If text is placed on top of an image, of the text. In unusual cases where the The complex intersection of colors consider the color relationships of With Adobe trapping technologies, to configure the placement of traps however, and the text is very light image data is composed of vector-like that occurs when design elements that the text and the background. Based the setting for such sophisticated traps between images and vector objects compared to the image data, a center- regions of highly contrasting areas, the overlap create complex intersections on these relationships, the trapping can be easily modified by the operator depending on the color relationship line trap risks choking the text, and trapping system should analyze the that require special trapping elements. system builds the appropriate to change the resulting trap elements. between them. In most cases, where thus rendering it unreadable. Adobe relative darkness of the two sides of trapping elements. images are simply abutting or knock- trapping technology can be used to the boundary at each point, and revert Text over continuous-tone images ing out of larger vector objects, a choke the image data in these cases, to the normal mode of placing the If typographic elements pass over Adobe trapping technologies are trap that straddles the boundary causing the text to spread and retain trap as is done between vector objects. photos or other continuous-tone capable of making such sophisticated consistently and doesn’t move from its intended appearance–including images, the intersection colors vary trap elements, which eliminate register side to side is more pleasing to the eye color–even in case of misregistration. significantly as the photographic error without introducing unsightly than one that moves back and forth in content is random. In these situations, color elements to the image. an attempt to spread the lighter color Conversely, if dark text is placed on the trapping technology must at all times. The default centerline a light image, the trapping system trap for image-to-vector trapping should spread the image data into the accommodates this situation. text to avoid an undesirable fattening disc Sampler Photo CD Photo Kodak the from fink Alan by Photo

In the illustration above, the vector illustration a job for the most sophisticated trapping technology. overlaying the continuous-tone image creates a The illustration on the left isn’t trapped, while the When creating trap elements for text over Notice that the trap color, created by Adobe challenge for trapping systems. The ability to create illustration on the right is. (The trap elements are continuous-tone images, a trapping system must trapping technologies, changes according to the trapping elements that vary with the relationship exaggerated in the illustrations.) consider the colors in the continuous-tone image image color behind the lettering, and no trap is between the foreground and background images is under the text (This image hasn’t been trapped). generated where the lettering crosses a highlight in the image (indicated by the arrow). (The trap elements are exaggerated in this illustration.)

16 17 Trapping details Trapping details Clipping paths provide effective edges for trapping Where thin strokes need special handling

Adobe trapping technologies treat the trap element and both sides of the and Adobe InDesign provide consis- Knowing its limits If a trap element spreads into an area creating an aesthetic appearance edges of images with clipping paths as underlying objects. This commitment tent and predictable trapping results One trick of successful trapping is to where it is larger than the available rather than make an unsightly trap. vector objects rather than pixel-based to superior image quality and across applications, making for a acknowledge special circumstances space, Adobe trapping technologies images. Trap elements are created appearance distinguishes Adobe flexible and reliable trapping solution. that affect print quality. Trapping thin limit the trapping element to half of Workflow optimization and placed between clipping paths trapping technologies from others areas can be a challenge, because the the space available. This limitation The unique high-quality trap shaping and other vector objects on which in the industry. thickness of trapping element can ensures that traps never extend and thin element trapping capabilities they are superimposed, resulting in a exceed the thickness of the artwork or beyond the opposite boundary of of Adobe trapping technologies elim- better trap than simply spreading an Adobe knows the industry the space available for the element. a thin area. inate the tedious manual inspection equivalent pixel-based image. With its commitment to the graphic and editing of traps. Minimizing arts industry and knowledge of the A savvy trapping system can create Such consideration isn’t restricted workflow impact due to trapping is a The pixel colors of the underlying needs of graphic arts professionals, trapping elements for thin areas to typographic elements. Adobe requirement of a quality automated image along the edge of a clipping Adobe develops products that work and account for available space trapping technologies limit the trapping technology. path are used to create the trap colors, hand-in-hand to deliver top-notch The original fish image in Adobe and thickness of the original shape of any trapping element that rather than expanding the image results. Close relationships between Photoshop shows the clipping path design element. would extend beyond an adjacent into its outlying pixels. The method Adobe trapping technologies and drawn by the artist. Adobe trapping design element. used in Adobe trapping technologies Adobe PostScript 3, Adobe PDF, technologies uses this clipping path as Type poses trapping challenges a trapping boundary. ensures consistent colors between the , , The thin strokes of common letter Although these adjusted trapping styles are often thinner than the elements are necessarily smaller trap elements created to prevent than the basic trap thickness, Adobe register error. trapping technologies defer to Clipping Path

No Trap Extended Repeated Mask Trap Edge Trap

Superimposing images with clipping paths on vector resulting in a border of black pixels around the fish. In the Delicate typographic elements demonstrate the need letter, protruding into another area of the artwork. Adobe artwork creates a challenge for trapping systems. In example at right, Adobe trapping technologies repeat the for special treatment for thin areas. In the top example, trapping technologies (right) create the trapping element the example at left, the fish isn’t trapped against the pixels of the vector illustration behind the clipping path, the cyan letter needs trapping because of the potential but adjusts its size to half the available area so the trapping illustration of the fishbowl. In the middle illustration, the using the path to produce a more attractive product. (The for register error. In the bottom example, conventional element doesn’t extend beyond the edge of the adjacent image has been trapped by an unsophisticated method, trap elements are exaggerated in these illustrations.) trapping methods create an unsightly stroke around the color element.

18 19

Adobe technology solves trapping problems Adobe technology solves trapping problems Adobe technology solves trapping problems World-class trapping makes successful printing more practical World-class trapping makes successful printing more practical

Adobe trapping technologies are a Trap Color Reduction Black Width Internal Image Trapping Trap Join Style in trap elements. Though these practical and effective solution for Occasionally the color generated Larger trap widths are valuable with Internal Image Trapping turnsturns onon Trap Join Style specifies thethe shapeshape ofof points are sometimes the product of graphic arts prepress preparation. for a trapping element is too dark, black where the trap is largely obscured trapping for the interior of pixel- a join between two adjacent traps. the trapping algorithms, the corner They fit into production processes especially when trapping pastel or but the effect of register error is severe. based images. This option is designed Available styles include Miter, Round, mitering function reduces them to involving computer-to-plate and highly contrasting colors. A Trap Color to trap such images where color and Bevel. These styles are illustrated mitered ends, making the trapping filmsetter applications. Reduction can be entered to reduce Adobe trapping technology allows trapping is necessary. An example on the facing page. element more attractive. the intensity of the trapping elements a separate trap width to be specified might be a business graphic that has Years of development have helped making them more subtle. for black inks or any ink handled with been rasterized as a bitmap in Adobe Trap End Styles shape Adobe’s prepress technologies the trapping rules for black. Photoshop. Normal photographic Trap End Style is a trapping parameter into products that meet and exceed the Black Color Limit images generally don’t need to be that specifies how Adobe trapping needs of our users. Black Color Limit is a setting that Printers Marks trapped internally. technologies form the end of a trap let’s you control which black tints Printer’s marks–register marks, trim that touches another object. Trap The previous described in are treated as black. Lowering the and fold marks–are marks used for page Neutral Density ends may either miter away from general, the level of sophistication value of this setting causes tints of positioning and finishing. These marks Adobe trapping technologies calculate an adjoining object, or the lighter achieved with Adobe trapping black less than 100% to be processed shouldn’t be trapped. Adobe trapping which color to spread based on the trap color at the intersection of Occasionally a sharp corner is created technologies. These next pages for trapping using the rules of black technologies correctly identify objects relative neutral densities of two adja- three objects may wrap around to by trapping functions. describe the additional features that trapping. This setting is especially designated with 100 percent value in all cent colors. Neutral density isis a measuremeasure meet an adjoining trap. This later make the technology truly exceptional. useful in printing in environments channels as printer’s marks. of how dark an ink is. Each ink has its overlapping style is frequently used that have considerable dot gain. own neutral density parameter. with flexographic printing processes. Trap width setting Adobe trapping technologies don’t Trap width allows the user to set Black Density Limit create traps between a printer’s mark Settings to control neutral density Corner Mitering the width of the trap in points. Black Density Limit isis a user-defineduser-defined and a background, between any object control are available in Adobe trapping Corner Mitering is a unique auto- The minimum is 0 points, and the value that dictates the neutral density that lies on top of a printer’s mark technologies control dialog boxes. matic feature of Adobe trapping maximum is 8 points (0.11 inch). value at which, or above which, Adobe and the printer’s mark, nor does it For detailed instructions, check the technologies. It enhances the detail The vast range of values makes trapping technologies consider an ink create reverse traps along the edge of a software manual for the individual of trapped elements by preventing Adobe’s trapping features reduce the trapping possible for a wide range to be “black.” Any ink with a neutral printer’s mark. application. long miter points from being created corner to a more reasonable miter. of production processes, including density value higher than this value is screen printing and flexographic handled using the trapping rules for printing on coarse substrates where black trapping. larger trapping elements are appropriate.

Trap Join Trap End Styles Styles

No Trap Miter Round Bevel No Trap Miter Overlap 22 23

Adobe trapping technologies Adobe trapping in common workflows Adobe in–RIP Trapping Adobe trapping technologies deliver where needed . . . simplifies the trapping process

Adobe has developed trapping tech- based on Adobe PDF Trapper, and PageMaker add trapping controls The complex process of trapping parameters is made from one of the settings are stored, the process of nology for implementation at any in Adobe PostScript 3 RIPs with to Adobe PDF and PostScript files, can be carried out by a specialized device-specific setup options in trapping a job–no matter how point in the production workflow. in-RIP Trapping technology. By allowing flexible methods for trapping trapping application, by a page layout the print dialog box. complex–can begin with a few clicks making trapping available at critical jobs destined for different printing application, like Adobe InDesign, of the mouse. Whether trapping is to be done at the points in the workflow, Adobe processes. These tools reduce the or by a raster image processor (RIP) Complex combinations of trapping RIP, in prepress, or at the application offers the greatest flexibility for need for the designer to be involved that handles trapping as a part of instructions, including trap sizes, Adobe in-RIP Trapping is an efficient level, an appropriate Adobe trapping workflow optimization by allowing in trapping decisions, moving those imaging a job. neutral density settings, and others and effective method for managing solution is available, and all are based in customizing trapping to meet the decisions to the prepress operation. can be saved as a set and used according trapping in a prepress production on the same effective technology to needs of individual workflows. And Several manufacturers have licensed to the type of project being printed. facility because it quickly traps all deliver correct trapping elements for because these applications share the The following pages describe the Adobe in-RIP Trapping for inclusion potential situations of misregister. any printing situation. same core Adobe trapping technology, specific Adobe trapping technology in their output devices, and these RIPs For example, a set of trapping Adobe-enabled trapping workflows implementations and how to use provide speedy and efficient trapping parameters can be stored for offset Adobe in-RIP Trapping is licensed Years of development have been provide consistent trapping results. them effectively. on demand. printing at 150 lpi, and another set to Adobe technology partners for devoted to improving the state-of-the- stored for flexographic printing at inclusion in their Adobe PostScript art in trapping sophistication, and that The Adobe prepress application, All of the trapping functions described 85 lpi. Selecting one of the stored sets and Adobe Extreme output devices. effort has been embedded in Adobe InProduction, and page layout in this booklet are possible in those of parameters is as simple as choosing InDesign, in third-party applications applications, InDesign and devices where Adobe in-RIP Trapping the stored set by name, and printing. is implemented. Control of the trapping Once a series of custom trapping

DESIGN PRE-PRODUCTION PREPRESS RIP

ADOBE A ACROBAT PDF DISTILLER Adobe InDesign PDF DOCUMENT TRAPPER Document document with trapping TRAPPING TECHNOLOGY instructions FILM Yes

Adobe Is InProduction RASTER ADOBE trapping requested? IMAGE PLATE PostScript 3 PROCESSOR PDF DOCUMENT PDF Document with trapping data with embedded Interpreter trapping instructions No Print with embedded Trapping Adobe PostScript 3 RIP with Adobe in-RIP Trapping PDF DOCUMENT with trapping instructions Adobe PageMaker Print with document Application- Adobe in-RIP with trapping level trapping Trapping instructions

26 27 Adobe PDF Trapper Adobe PDF Trapper A trapping solution for Acrobat PDF documents A trapping solution for Acrobat PDF documents

Adobe PDF Trapper is native trapping In an Adobe PDF workflow, the job ticket. Alternatively, Adobe Adobe Extreme technology), an Benefits of PDF Trapper • Support for fully automated trapping technology that is licensed to Adobe page description is captured in the Acrobat Distiller can be configured Adobe PostScript 3 device, or other • Support for all of the features and batch trapping technology partners, enabling them PDF Page Contents portion of the to add default trapping parameters to PDF RIP. available in Adobe in-RIP trapping to build robust PDF-based trapping PDF document and the Job Controls the job ticket via a PostScript prep • Support for selective retrapping solutions. and device-specific information file or the Distiller startup.ps file. Because the trapping elements created • Trapped PDF files for preview in of individual pages in Adobe PDF are captured in a job ticket. The job by Adobe PDF Trapper are added as Adobe Acrobat software (5.05 and documents Adobe PDF Trapper technology ticket is either embedded in the PDF PDF Trapper analyzes the PDF page an annotation layer to the PDF file, higher) or other viewers that support provides high-quality trapping targeted document or stored in an external file. contents and builds a trapping display traps can later be removed or revised. Overprint previewing • Acceptance of trapping instructions at PDF workflows. It is based on the list, which is later trapped by Adobe A PDF file may contain multiple specified by open standards instead same core trapping technology as Users can specify trapping controls trapping technology. PDF Trapper TrapNet annotations targeting dif- • Ability to store multiple sets of traps, of proprietary trapping control Adobe in-RIP Trapping. in the job ticket; PJTF job tickets generates traps and stores them as a ferent printers, and the operator can each destined for a different output software supported now and JDF job TrapNet annotation layer in the PDF then select the appropriate TrapNet device Adobe Portable Document tickets will be supported in future file in conformance with PDF/X and annotations for the target printer. • Support for both internal and Format/Portable Job Ticket Format implementations. PDF 1.3 and higher. Optionally traps • Support for a trap-once, print external job tickets Adobe PDF makes it possible to may be added to the PDF page content In addition, by enabling or disabling multiple times workflow separate content-specific information Adobe Acrobat Distiller can be for workflows that don’t support TrapNet annotations, the operator • Compliance with Adobe PDF and from device-specific information, configured to create a PJTF job ticket PDF annotations. can print with or without traps. This • Ability to bind traps to Adobe PDF Portable Job Ticket Format providing greater flexibility in from a PostScript file and embed implementation allows users to print files, unloading trapping from RIP a workflow. that job ticket in the resulting PDF The trapped PDF file can then be or proof the trapped PDF file. • Support for trapping of PageMaker®, document. Trapping parameters in printed to an Adobe Printer Job Ticket • Support for advanced color handling InDesign, and QuarkXpress the PostScript file are added to the Processor (in a system employing options for device-dependent and PostScript files distilled by Adobe device-independent color workflows Acrobat Distiller

PROOF/REVIEW CYCLECLE RE-TRAP VIEW A Automated and Batch Trapping PDF DOCUMENT Print with trapping Adobe PageMaker with trapping data to device A publication PDF DOCUMENTS for device A

PDF ADOBE TRAPPER A ACROBAT DISTILLER PDF DOCUMEN Print with trapping PDF DOCUMENT PDF DOCUMENT Adobe InDesign with trapping data with trapping data to Device B document for device B

ADOBE A INPRODUCTION STORED TRAPPED A PDF DOCUMENTS PDF DOCUMENT PDF DOCUMENT PDF DOCUMENT Print discarding with trapping data Document from with job ticket trapping other application discarded

28 29 Adobe InDesign 2.0 Adobe InDesign 2.0 How to use InDesign trapping features How to use InDesign trapping features

Specifying trapping parameters 4. In the pop-up menu of the Trap 7. Select what type of trapping you Adjusting Ink Information settings only if needed (for example, Overprinting black when printing from Adobe InDesign Style ppalettealette sselectelect Assign Trap Styles. want to use, either Application The Ink Manager is accessible from if required by the printer or service By default, InDesign overprints 1. With your InDesign document Built-In Trapping, or in-RIP either the Print dialog or the Swatches bureau). all objects to which you’ve applied open, select the Trap Styles palette 5. Select the Style you want to assign Trapping. In order to use in-RIP palette. The Ink Manager controls black in the Swatches palette, and in the Window menu, then choose to your page or page range, then Trapping you must have a RIP settings for all of the characteristics Trapping Zones it overprints all Black strokes, fills, Trap Styles. enter the page range and click and a PPD that support in-RIP of inks that influence trapping. InDesign 2.0 honors full page Zones and type characters. You can disable Assign; this enters your page. You trapping. You must select in-RIP The default settings work for most only. The page size, including bleed, this default in the Overprint Black 2. In the pop-up menu of the Trap can now enter more page ranges, or Separations before you can choose jobs, but some jobs may require is the size of the trap zone. InDesign preferences setting. If you disable Style palette select New Style. save the settings by clicking Done. in-RIP Trapping in the Print dialog. adjustments. For example, when 2.0 allows you to trap a page spread Overprint Black, all instances of With Application Built-In Trapping you create a varnish plate, selecting with two different trap zones. The black will knock out (remove 3. Configure all settings to match 6. In the print dialog, click on Output you can select either method of Transparent forces the color not to document can be trapped more underlying inks). your job’s needs, then name on the left, then select the mode separations, and any PPD that be trapped. The Ink Manager also quickly if you disable trapping for the Style and click OK. Note: of separations that you want to supports separations will suffice. provides control over Neutral Density pages that don’t need it. You can For detailed information on specifying Application Built-In Trapping is use, either in-RIP or Built-In which establishes which colors will disable trapping in the Assign trapping parameters from Adobe limited to a trap size of 4 points Separations, you must select one spread into other colors. Ink Sequence Styles menu. InDesign, please refer to the Adobe (0.055 in.) while in-RIP Trapping method of separations in order to is also set here to control the order in InDesign 2.0 User Guide. can create trap elements up to 8 use either form of trapping. which colors print. (The order can points (0.11 in.). also affect trapping). Change these

In the Assign Trap Styles dialog box, individual pages and The Modify Trap Style Options dialog box controls the ranges of pages are assigned trapping styles (created in the The Ink Manager allows you to assign inks, set the named styles for trapping, making it easier to apply previous dialog box). In this example, page 2 is set with neutral density of an ink, and set the sequence in the styles in subsequent dialog boxes. the No Trapping style, page 1 with the Big Trap style, and which inks print. In this example, is defined pages 3-5 with the Litho style. as an opaque ink, which controls how that ink will trap relative to the other colors.

Open the Ink Manager from the Print dialog box.

30 31 Adobe Acrobat InProduction Adobe Acrobat InProduction How to use Acrobat InProduction trapping features How to use Acrobat InProduction trapping features

1. Open the Trapping dialog box. 3. Apply trapping settings by doing select and adjust the trapping won’t spread. Then ensure that 5. Under New Style, make selections For more information on specifying one of the following: specifications for the default page inks are set to print in the for Trap Width, Trap Threshold and trapping parameters, here, see the 2. Select Enable Trapping to turn on zones you want to change, or you proper order. Images can be set. These settings Adobe Acrobat InProduction trapping. The first time you • To apply the same trapping must create new zones on each are similar to those found in Adobe User Guide. enable trapping in a document, settings to the entire document, affected page. Pastel inks are normally lighter InDesign, and they allow you to Adobe Acrobat InProduction click OK. Then choose File > than their process equivalents. set Sliding Trap and Trap Images automatically creates an invisible Save As, and save the document 4. For each document, you can adjust You may want to set the neutral Internally (features not available trap zone around each page and using a new name. Using the Save any ink’s neutral density or ink density value for these inks lower in Adobe InDesign 1.5). applies the Device Default style. As command keeps the original type that is used by Adobe in-RIP than their default values to ensure This style instructs the RIP or job PDF file intact. Trapping to determine the precise that they spread into any adjacent Setting Trap Styles is recommended ticket to specify trapping controls placement of traps. In general, you darker colors. for routine printing processes. These for each page according to device- • To specify different trapping should set the ink type of metallic styles can produce consistent and specific parameters. settings for specific areas in or opaque spot colors to Opaque reliable traps. a document, you must either to ensure that these spot colors

The New Style dialog box allows trapping Styles to be created. Trap Widths are set in this window. Notice Additional detail settings are made in this that black can have a different value than the This pop-up menu menu. Note that Sliding Trap can be set there. other colors in a document. opens the Inks palette. Neutral Density settings can be modified in this window.

32 33 Adobe PageMaker Adobe PageMaker How to use PageMaker trapping features How to use PageMaker trapping features

To use the in-RIP Trapping plug-in, Trap Style settings The in-RIP Trapping plug-in gives you To get a color to behave as a subor- • Choose Transparent for varnishes prevent trapping along the ink’s copy it into the Adobe PageMaker The Styles dialog box lets you fine- tools for handling these situations. dinate color being spread into other and other clear inks to ensure edges. Use this option for inks that plug-ins folder. After you install tune the trapping settings for each In the Inks dialog box, choose Modify colors, reduce the neutral density trapping of underlying items. have undesirable interactions with the plug-in, the in-RIP Trapping style you create. to reach the Current Ink dialog box value. To make the ink behave as a Use this option for varnishes other inks. command appears in the Utilities > where the color’s characteristics dominant color, increase its neutral and die line inks. Plug-ins menu. Working with specialty inks can be modified for the trapping density to a value higher than the For more information on specifying Certain inks require special trapping controls. It is in this dialog box that value of the ink you wish to see • Choose Opaque for heavy, non- trapping parameters using the To download the latest version of this considerations. For example, if neutral density is set. A measured spread into this color. transparent inks to prevent trapping Adobe in-RIP Trapping plug-in for plug-in, go to Adobe’s Web site at http: you use a transparent varnish on neutral density can be made with a of underlying colors but to allow PageMaker, see the Adobe in-RIP //www.adobe.com/support/downloads/ a publication, you want traps for densitometer on a sample of the actual Ink Type is another option in this trapping along the ink’s edges. Use Trapping User Guide, a PDF file main.html. colored items underneath as if no ink, and then entered into this dialog, dialog box. The choices for this this option for metallic inks. included with the Adobe in-RIP varnish were present. Alternately, or you can use the Adobe PageMaker option include the following: Trapping plug-in. Trap styles if you overprint certain areas with defaults, and modify the ink’s • Choose Opaque Ignore for heavy The in-RIP trapping plug-in lets you a metallic ink (which is completely neutral density to force the trapping • Choose Normal for traditional non-transparent inks to prevent customize trapping settings and store opaque), you don’t need to create algorithms to treat the process inks and most spot inks. trapping of underlying colors and groups of settings as Trap Styles. traps for items underneath. color differently.

The Current Ink dialog box lets you change an ink’s neutral density and its type. This dialog box describes the inks and their printing order. To change the order, select the ink color, and click the Move Down button. To change neutral Trapping settings are made in this dialog box, including density, click the Modify button. trap thickness and black width, which can be different This pop-up menu opens the Styles and Inks dialog boxes from the other colors in a publication. (right). After set-up is complete, clicking OK enables trapping to occur at the time of printing. Note that the PageMaker in-RIP trap plug-in works with Adobe PostScript in-RIP systems.

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Adobe technology partners Where to find Adobe trapping technologies Adobe Trapping technology partners

Agfa Corporation Heidelberg 200 Ballardvale Street 1000 Gutenberg Drive Wilmington, MA 01887 USA P.O. Box 100003 978-658-0200 Kennesaw, GA 30144-9203 USA www.agfa.com 770-419-6657 www.heidelbergusa.com Dainippon Screen Mfg. Co., Ltd. Tenjinkita-cho 1-1, Teranouchi-agaru 4, IPTech Horikawa-dori, Kamigyo-ku 2925 McMillan Avenue, Suite 202 Kyoto 602-8585, Japan San Luis Obispo, CA 93401 USA 81-75-414-7111 805-541-3000 www.screen.co.jp www.iptech.com

FUJIFILM Electronics Imaging Ltd. Monotype Systems Incorporated Fujifilm House 2100 Golf Road Boundary Way Rolling Meadows, IL 60008 USA Hemel Hempstead 847-427-8800 Herts HP2 7RH www.monoexpress.com United Kingdom +44-1442-213440 RIPit Computer Corporation www.ffei.co.uk 7920 Alta Sunrise Drive, Suite 250 Citrus Heights, CA 95610 USA 916-962-7050 www.ripit.com

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