Conservation 2000 3 Number 5, 1 olume V ■ The Getty Conservation Institute Newsletter The Getty The J. Paul Getty Trust Barry Munitz President and Chief Executive Officer

Conservation Stephen D. Rountree Executive Vice President and Chief Operating Officer Institute John F. Cooke Executive Vice President, External Affairs Newsletter Russell S. Gould Executive Vice President, Finance and Investments

The Getty Conservation Institute Volume 15 , Number 3 2000 Timothy P. Whalen Director

Jeanne Marie Teutonico Associate Director, Field Projects and Conservation Science

Kathleen Gaines Assistant Director, Administration

François LeBlanc Head of Field Projects

Alberto de Tagle Chief Scientist

Marta de la Torre Head of Information & Communications

Conservation, The Getty Conservation Institute Newsletter

Jeffrey Levin Editor

Joe Molloy Graphic Designer

Color West Lithography Inc. Lithography

The Getty Conservation Institute works internationally to advance conservation practice in the visual arts—broadly interpreted to include objects, collections, architecture, and sites. The Institute serves the conservation community through scientific research into the nature, decay, and treatment of materials; education and train- ing; model field projects; and the dissemination of information through traditional publications and electronic means. In all its endeavors, the GCI is committed to addressing unanswered ques- tions and promoting the highest possible standards of conservation.

The Institute is a program of the J. Paul Getty Trust, an international cultural and philanthropic institution devoted to the visual arts and the humanities that includes an art museum as well as programs for education, scholarship, and conservation.

Conservation, The Getty Conservation Institute Newsletter, is distributed free of charge three times per year, to professionals in conservation and related fields and to members of the public concerned about conservation. Back issues of the newsletter, as well as additional information regarding the activities of the GCI, can be found in the Conservation section of the Getty’s Web site. http://www.getty.edu/gci

Front cover: Detail of James Ensor’s painting Christ’s Entry into Brussels (1889) being The Getty Conservation Institute cleaned in 1988 with the gels cleaning process. The GCI is currently conducting a 1200 Getty Center Drive, Suite 700 research project to answer questions Los Angeles, CA 90049–1684 regarding the long-term effect of cleaning with the gels systems. Photo: Mark Leonard. Telephone: 310 440–7325 Fax: 310 440–7702 Contents News GCI Conservation News in Dialogue Feature 23 16 10 20 5 a common agreement of the historical uniqueness of every artistic or cultural relic. every orcultural artistic thehistoricaluniquenessof of agreement a common seemstohave relieson cleaning that one beenreached, theproblems of of understanding T genuine age, waslessfavored cleaning originandtrue by many. astestimonyappreciated of purityandintegrity. periods, Inlater were whendecay andpatina stood asasymbolof hasbeenunder- cleanliness history.has hadalong of Sinceancienttimes, thecondition andhistoricmonuments—as anevolving art ideaandinpractice— works of of The cleaning Updates on Getty Conservation Instituteprojects, events, Getty Conservation on Updates publications, and sta Projects, Events,Publications, andStaff As St.Petersburg for prepares its labpractice. The systems arenow widelyusedinconservation advantages, important thesecleaning community.systems totheconservation Becauseof In theearly The GelsCleaningResearchProject c tothesurface issuesrelated thephilosophicalandtechnical antiquities—discusssomeof of paintings, Podany andJerry andsculpture, decorativearts of MarkLeonard of Considine departments—Brian headupGettyMuseumconservation that Three conservators Finding aCertainBalance Surface CleaningandConservation tion services, collaborativescienti tion andtraining, informa- ineducation programs throughprofessional strategies conservation in St.Petersburg, modern andfacilitate theUnitedStates, andEurope—istoencourage institutions of by backed acoalition organization theCenter—anindependent of mission in thisWorlddevoted preservation exclusively heritage tocultural City. Heritage The organization noncommercial isassumingavitalroleastheonly Center for Preservation on University, research outin-depth Northridge, andtheGettyMuseum—hasbeencarrying State California of theChemistryDepartment Conservation, inArt Delaware Program of theWinterthur Museum,Gardens, at colleagues andLibrary, theWinterthur–University Preservation inSt.Petersburg enn fobjectsinmuseum collections. leaning of oday, historians, art between andscientists, conservators, abalanced withcooperation

the gels cleaning systems and their long-term e systemsandtheirlong-term the gelscleaning  s,

ihr obr fteUiest fDelaware introducedgelscleaning theUniversity of Richard Wolbers of fi  A DiscussionaboutSurfaceCleaning c research, and heritage advocacy. andheritage c research, th birthday in th birthday ff ects on paintedsurfaces.ects on  , theSt.Petersburg International  —in collaboration with —in collaboration ff . conservation of The Last Judgment, the th-century glass mosaic A that is one of the Czech Republic’s most significant cultural trea- Note from sures. During this year, the —in collaboration with colleagues inside and outside the Getty—continued conducting scientific D c research that has made strides in addressing questions regarding the ire or gels cleaning systems. Several projects involving the conservation and management of sites are ongoing in Central America, the By Timothy P. Whalen Mediterranean, and China. In the year ahead, we have a meeting planned in Spain on retablo conservation and a workshop scheduled for Brazil on build- ing-related aspects of environmental management. We will begin I          the Institute’s research with our partners at the Image Permanence Institute— work in these pages, and I want to take this opportunity to update and at the Centre de recherche sur la conservation des documents you on our progress. graphiques in Paris—on the conservation of photographic collec- There are several significant staff changes that I’m delighted tions. And we’ll explore research needs related to the conservation to announce. Jeanne Marie Teutonico has been named associate of modern and contemporary art, in collaboration with a number director for Field Projects and Conservation Science. This of major art museums. appointment should help us integrate the work of these two Art and Archaeology Technical Abstracts (AATA) is being groups in a way that strengthens our contributions to the field. strengthened, and within  months we will launch it as a Web- I am also pleased that François LeBlanc—chief architect at the based resource, in partnership with our colleagues at the . As we National Capital Commission in Ottawa, Canada—will join us expand its coverage and make it more accessible and comprehen- as head of Field Projects. We are honored to have him lead this sive, we are grateful for the tireless efforts of AATA’s technical important program. editors and volunteer abstractors, without whom the publication Since I arrived at the  two years ago, we have assessed our would not exist. strengths, focused our work to complement that of the Getty Trust, Locally, we are working with the City of Los Angeles on the and consolidated our activities in our traditional areas of expertise. conservation and presentation of the David Alfaro Siqueiros mural Ultimately, our raison d’être is to serve the field of conservation by América Tropical. We have a generous partner in our local support providing tools and resources for those responsible for the care and group, Friends of Heritage Preservation, and we anticipate— conservation of art, architecture, and archaeology. To do that, we pending city approvals—that the mural will be accessible to the are organized into four groups: Conservation Science, Field Pro- public in . jects, Education, and Information and Communications. Each I hope you’ll visit the Getty’s newly launched Web site: group includes highly dedicated staff who work with a wide array of http://www.getty.edu . It incorporates all the Getty Trust’s institutional partners and colleagues—and with our conservation activities, including descriptions of the ’s work and a range of colleagues in the other Getty programs. conservation resources. Please let us know what you think of the We will soon name a head for the Education Group, which is conservation components of the site by writing us at: quickly taking shape. I’m pleased with the response to the ’s [email protected] . new visiting scholars program, which offers an opportunity for Because the needs of the conservation field are vast, no single conservation professionals to examine important questions, freed organization can provide all the resources and solutions necessary from the grind of practice, lab, and field. The Education Group to address them. I expect, however, that anything the Institute pur- will contribute essential resources to individuals and institutions sues will broadly serve the conservation community, in part because that teach conservation, in part by publishing important readings we work with conservation organizations and professionals around in conservation as well as translations of significant works. We will the world who offer skill and expertise that complements our own. continue to work closely with the conservation training programs I’m grateful to our partners—and to the staff of the —for the to examine ways that the teaching of conservation professionals commitment and talent they bring to advancing conservation can be advanced. worldwide. Please accept my best wishes for the holidays and for During this last year, we had some notable accomplishments, peace in the new year for you and your family. including the Second Pan-American Course on the Conservation and Management of Earthen Architectural and Archaeological Heritage, held in Peru. This summer saw the completion of the

4 Conservation, The GCI Newsletter lVolume 15, Number 3 2000 lDirector’s Note and Conservation Surface Historisch Museum. Photo: paintings ownedbythemunicipality. for thecleaningandrestorationof made numerouspaymentstovanDijk 1746 and1766,theCityofAmsterdam painted byJantenCompe.Between The 1754portraitofJanvanDijk, By ManfredKoller Courtesy theAmsterdams T Cleaning and on monumentsanoutdoorone). (representing and on f my andconservation, cleaning be solved. Inthefollowing review of apply new thesurface—have protective on andunifyingcoatings to lossorwhethernotto ashowissues—such topresenttheareasof cleaning, other early times. Inmany instances, of asaconsequence since hasbeenunderdiscussion forpast; cleaning aestheticreasons necessityhasbeen nearlyoverlookedCleaning asatechnical inthe for aestheticorotherreasons. itusuallyisdone conservation, di andhistory, art have cleaning regarding torespect discussions of theviewer’s on depend consciousness, experience, andknowledge andreactions aswell.visual changes Becausevisualsensations theviewer, thereare the objects. From thesubjective standpointof of resultsinsubstantialphysical tothesurface generally changes T f GreekandRoman towns Thebuildings andplacesof important. v of presentation priestsortheimmaculate dressing andthefood of for the therules example,purposes—for of asacomponent purity andintegrity. for religious asapurgative Cleaningserved asa symbolof hasalsobeenunderstood cleanliness of condition dullslusterortransparency.that But sinceancienttimesthe signi The literal ocus is primarily on painting (representing anindoorenvironment) painting(representing ocus isprimarilyon ollowed guidelines for public certain order. Inmedieval central enerated statues. Even in profane life, the idea of cleanliness was cleanliness statues.enerated Evenlife, inprofane theideaof    ff erences in cultural background and visual education. andvisualeducation. background erences incultural h vligIe fCleaning The EvolvingIdeaof While cleaning can be a technical necessityfor canbeatechnical proper While cleaning Conservation, TheGCINewsletter fi cance of clean is free of dirt, stains, dirt, oranything isfreeof clean cance of and historicmonuments l V olume 15 , Number 3 2000 l Feature 5

Feature Italy, new communities set up rules to maintain the visual harmony of their buildings in order to assure positive public representation of townships. This concept continued until the th century with public control of civic buildings. Often cleaning has been connected with the celebration of anniversaries, done to show physical and visual rebirth—in Latin called renovatio or restitutio. Between  and , churches in Rome were whitewashed every  years to celebrate “holy years.” With the development of science and of philosophical concepts of rationalism in the Age of Enlightenment, a basic refor- mation in economics, society, and the arts occurred. When Isaac Newton identified the spectral composition of light around , the nature of pure color became evident for the first time. It cannot be accidental that shortly thereafter, following debates in the acad- St. Peter’s Basilica in the Vatican after being cleaned emy of arts in Paris, the priority of color was officially emphasized. in honor of the Jubilee Year 2000. In the 17th and 18th centuries, Roman churches were washed every 25 years Similarly, in Venice, the dark tonality of paintings (from the so- in honor of “holy years.” Photo: Marta de la Torre. called tenebrosi painters) changed to a bright and clear palette. The theory and the practice of art have always influenced those of varnishes and dark surfaces became fashionable as a way to evoke restoration, as has the general development of society and mind. sentimental feelings of mystery and ideal harmony. This corre- (For example, after the American wars for independence and the sponded to the contemporary philosophy of aesthetic idealism. French Revolution, the ideals of liberation and freedom became Technical problems in cleaning pictures were discussed in dominant; in the following period of romanticism, cleaning was many painters’ books before and after , following the growing given even a moral value as liberation from all earlier alterations— professional specialization of “restorer.” This specialization was a recovery of the “original” nature of material and the believed guided by leading members of the art academies. They oversaw authentic creation of the artist.) the practice of restoration of public patrimony and also prevented The first definitions of cleaning and patina related to works radical cleaning of outdoor sculptures—for example, the Trinity of art were noted by Tuscan artist Filippo Baldinucci in the latter Column monument in Vienna in . New understandings of part of the th century. In his Italian vocabulary, to clean (pulire) architectural surfaces were revealed in the debates about poly- means not only to take away dirt and stains but also to polish— chromy in antiquity. The protagonists—architects Leo von Klenze mainly marble and metal. He called patina (patena) “some univer- and Gottfried Semper in Germany and Jacques Ignace Hittorff in sal darkness which time made to appear on pictures and that France—approved of the presence of color, as opposed to the neo- sometimes favors them.” This remark reflects the view already held classic ideal of the pure material devoid of color. by the antiquarians and connoisseurs of the time. But patina and In the middle of the th century, with mainly medieval other darkness were appreciated in other respects. It was forbidden architecture in mind, John Ruskin was the first to condemn all to clean certain venerated religious statues or paintings such attempts at uncovering and radical cleaning as destruction of what as icons, and only tinted varnishes were periodically applied; should have been preserved. “The whole finish of the work was in over time, these became nearly black, a condition that was desirable the half inch that is gone,” he wrote. “Take proper care of your for its mystic appearance (an example is The Black Madonna of monuments, and you will not need to restore them.” This admirer Czestochowa, Poland). of the “stones of Venice” was closely followed by Camillo Boito, Another antiquarian idea against cleaning during the th who, on behalf of the cathedral at Murano, fought “against the century was the appreciation of decay and patina as testimony of cleaning, the washing, and the renovation which destroys stains and genuine origin and true age. Pieces in this kind of condition colors produced by the great Time.” brought a good price in the art trade. William Hogarth offered a By , the call for “conservation instead of restoration” critique of this esteem for age in his famous and ingenious  had grown strong in many European countries. In , Austrian engraving Time Smoking a Picture. The inscription below the art historian Alois Riegl published his fundamental thoughts engraving connects it to the paradox of a contemporary intellectual regarding the values of the past (age, history, and memory) and the controversy: “As Statues moulder into Worth.” From the late present (use, artistry, and novelty). Behind his “value of age” was th century and into the th century, the application of colored his belief that all works are subject to decay as part of their history.

6 Conservation, The GCI Newsletter lVolume 15, Number 3 2000 lFeature Their present appearance, he believed, should not deny or hide fact that restoration had been done. For example, in his – their fate. restoration of the wall paintings by Raphael in the Vatican, Carlo Riegl’s values are based on a historical and humanistic Maratta, head of the Academy in Rome, left an uncleaned area approach but also include the practical functions of any interven- down in the School of Athens. The restorer in habit of an artist tion. The opposite approach relied mainly on the results of can be seen in Jan ten Compe’s  portrait of Jan van Dijk (the scientific examination of materials and techniques. A scientific role painting restorer for the City of Amsterdam) cleaning a landscape in conservation interventions began to increase in the first part of painting. Van Dijk, a cotton swab in his left hand, sits in front of his the th century, though as early as  in Paris, artist and dealer easel, dishes and bottles for liquids on a small board to the side. Jean-Baptiste-Pierre le Brun invited chemists to assist in the repair Yellowed varnish has been cleaned from the upper right part of the of a gallery in the national museum. During the th century, landscape painting. scientific research on the technology of art was firmly established. Just four years later, Robert Dossie provided detailed infor- The first activity in the Anglo-American countries focused on the mation about cleaning practice for painted surfaces in his Hand-  exhibition of cleaned paintings in the National Gallery in maid to the Arts. He noted that “the art of cleaning pictures and London, which was followed by very fertile discussions of the paintings is of great consequence in preserving valuable works of “cleaning controversy.” that kind, but has been very little understood even by those who At present—with the intense cooperation between conserva- profess to practice it.” Dossie criticized situations in which no tors, art historians, and scientists—a balanced and complementary thought was given to the different circumstances and to the effect understanding of the problems of cleaning finally seems to have of various solvents. He emphasized the need to retain the varnish been reached. This understanding generally relies on common when its removal was not necessary or when cleaning an oil painting agreement of the historical uniqueness of every artistic or cultural would be a risk, while at the same time he advised “the taking off relic as an authentic document in all its individual aspects—an any foulness . . . by dissolving . . . the matter that constitutes it.” agreement that has been codified in the various charters for the He systematically listed a range of cleaning mediums from low to restoration of art, architecture, and archaeology since . high strength, including water, olive oil, butter, wood or pearl shell ash, soap, spirit of wine, oil of turpentine, and essence of lemons. A Brief History of Cleaning

In antiquity, the application of lye (followed by polishing) was reportedly used for washing statues. The Romans valued and retained metallic patinas, mainly on ancient Greek works in bronze. For facades and interior rooms, since medieval times, periodic cleaning mostly meant new paints in different colors to give a new interpretation. Similarly, repainting and alteration were performed for many polychrome sculptures and mural and easel paintings. This making clean and looking new with repaintings—and some- times gilding—for religious sculptures or church furnishings lasted until the th century. Regarding the general idea that cleaning should help make things look fresh and new, we should recall the double meaning of the Italian pulire as cleaning and polishing, as defined by Baldinucci. Old sourcebooks indicate an early practical knowledge about cleaning agents and their connec- tion with revarnishing. Until the late th century, restoration was usually performed by artists, often as part of their function as keepers of collections. Only slowly did restoration become a special profession of art— a development that emerged first with paintings. The cleaning of a William Hogarth’s 1761 engraving Time Smoking a Picture, picture apparently was judged to be a task of art. Even Baroque the artist’s commentary on the monetary value many in his painter-restorers, however, were aware of the need to document the time placed on items that showed evidence of age and decay. Photo: Courtesy the Huntington Library.

Conservation, The GCI Newsletter lVolume 15, Number 3 2000 lFeature 7 The section on the cleaning of pictures and paintings in Robert Dossie’s mid-18th- century book Handmaid to the Arts. Dossie offered specific cleaning techniques for painted surfaces. Photo: Courtesy Special Collections, Getty Research Library.

Dossie’s approach was copied by many until the th century, by the International Institute for the Conservation of Historic and and such practice continued even after . The old idea of Artistic Works, and since  by the International Council of refreshing surfaces was given new scientific support by chemist Museums Committee for Conservation—the international debate Max von Pettenkofer with the use of solvent vapors for reforming on all aspects of cleaning, from theory to practice, intensified and the surfaces of degraded varnishes—a process that was patented continues today. in Munich in the mid-th century. As a way to avoid the darkening Since the s, totally new perspectives have been intro- of varnishes based on oil and/or mastic—and for ease of reversibil- duced into conservation, particularly in the treatment of surfaces ity—Friedrich Lucanus introduced dammar resin into restoration of works of art and monuments. On the diagnostic level, the under- practice in . He also advised restorers to note, on the back standing and definition of the characteristics and the condition of every picture that they restored, the materials they had used in of surfaces have deepened, and new instruments, such as microtools their work. and lasers, have offered ways of mechanical/physical cleaning In the field of mural painting, many now-famous pictures previously not possible. On the chemical level, a wide range of (including The Last Supper by Leonardo da Vinci) had been white- newly tested products—including solvents, soaps, and enzymes— washed years after their creation. Removing these superimposed have come onto the market. But even more important has been the layers became fashionable during the second half of the th improvement in controlling solvent action through the use of poul- century and was done mainly mechanically by scraping. Works on tices (with fillers) and pastes or gels for precise control of the area, stone were treated even more severely. Crusts of deposits—together penetration, and time. with the corroded original surface (including original tool marks In the field of stone, plaster, and wall paintings, many surfaces and colorings)—were reduced by chisel and hammer, as was done currently show severe damage from chemical transformation by stonemasons for most medieval cathedrals in Europe after about caused by external deposits or internal transport of acidic or basic . In northern and western Europe in the later part of the th salts. Readily soluble salts can be extracted, but to deal with some century, cleaning with hydrochloric acid and impregnation with types of damage processes, several methods for chemical passivity sodium silicate caused other types of long-term damage to both have been developed over the last  years for specific cleaning painted walls and stone works. By then, sandblasting had come into needs. Similar to the approach of revarnishing painted surfaces use for cleaning works of stone and stucco. after cleaning is the concept of “sacrificial layers”—a reversible The introduction of new and more efficient techniques for protective coating and a buffer against weathering. This technique cleaning was mainly the fruit of closer collaboration between con- has proven successful for unpainted plaster and sandstone. The servators and scientists after . This development was sup- possibilities for applying new methods have substantially changed ported by the establishment of interdisciplinary centers for not only the quality but also the delicacy and accountability of con- conservation and research—the Istituto Centrale per il Restauro in servators’ choices of cleaning interventions on the inorganic sur- Rome, the Doerner-Institut in Munich, and the Institut Royal du faces of monuments and on organic substrates, such as paintings, Patrimoine Artistique in Brussels, among them. With the start of paper, and textiles. professional conferences—for example, those organized since 

8 Conservation, The GCI Newsletter lVolume 15, Number 3 2000 lFeature An Irreversible Intervention

The surface of a work of art must be taken as an archive of its own history, from its creation to the present. In many cases, the real sta- tus of a piece, in terms of its origin and history, is little—if at all— known. This fact makes all the more valuable every artwork still left uncleaned. Its untouched integrity offers two opportunities—a sen- sitive one, for the evocation of hidden artistic values, and another one, for research regarding technology and history of the piece. These two opportunities are often counter to each other. Moreover, if all later additions are removed in an attempt to return a work of art to its “original” status, inevitably the “archive” of time and history is destroyed. The “original” surface in reality no longer exists, having suffered several transformations through time. The idea of recovering any “true” original is therefore an unrealistic one. Cleaning has implications both for conservation and for restoration. As it is an irreversible intervention, every decision and Detail of a half-cleaned 17th-century marble sculpture on operation is one of major consequences. The methodology for the exterior of Salzburg Cathedral. Photo: Manfred Koller. undertaking this intervention was clearly put forth by historian and critic Cesare Brandi, who laid out the criteria for examination A partially cleaned portion of an early 18th-century of a work of art: material and technique, history, and aesthetics. vault painting by Giovanni Antonio Pellegrini in the Salesianerinnenkirche in Vienna. Photo: Manfred Koller. Together they form what Brandi calls “the potential unity of the work of art,” and they must be considered for cleaning, as well as for retouching. Paul Philippot has described the double reality of any object of art—that it contains both material/technical, and historical/ aesthetic aspects. The task for the conservator is to maintain the proper balance between these two. “From a critical point of view,” he writes, “cleaning then becomes the search for an achievable equi- librium that will be most faithful to the original unity.” When that equilibrium is achieved, the result could be seen less fatalistically than art historian Max J. Friedländer perceived the process nearly a half century ago: “The job of the restorer is a most thankless one. In the best case, no one is aware of him. . . . His mastery remains invisible, but his failing becomes evident. . . . Restoration is never- theless a necessary bad thing.”

Manfred Koller is the head of the restoration department of the Austrian Federal Office for Monuments (Bundesdenkmalamt), a lecturer at the Universities of Art and Science in Vienna, and coeditor of Restauratoren- blätter, a periodical of the Austrian Group of the International Institute for Conservation of Historic and Artistic Works (IIC).

Conservation, The GCI Newsletter lVolume 15, Number 3 2000 lFeature 9 Finding a Certain Balance A Discussion about Surface Cleaning

The Getty Conservation Institute Alberto de Tagle: When I first started to work on conservation- is currently conducting a research related scientific issues in the early s, one of the main project that addresses one of the problems that conservators presented to me was surface cleaning. Dialogue critical issues in conservation: the Conservators wanted to know what was really happening in the cleaning of surfaces of art objects. cleaning process. Since then, I’ve felt that this was a very impor- Cleaning the surface of an object— tant question that needed to be addressed in general terms. which ranges from dirt removal to At this roundtable, I’d like to talk about some of the issues replacing a degraded varnish—can of surface cleaning from the conservator’s point of view. I’ll start raise a series of questions regarding with an issue at the forefront of discussions of surface cleaning aesthetics, the potential loss of philosophies, which is that of patina—that much-prized change historical information, and the of the surface that comes with age. How do you define “patina,” ability to control the cleaning and how do you keep it when cleaning and removing the undesir- process adequately. able changes that occur with time? The GCI research project attempts Jerry Podany: The complexities of an archaeological artifact’s to answer some important questions surface, or its patina, have been known for some time and certainly regarding the use of solvent-based appreciated for aesthetic beauty since antiquity. But the wealth of gels as cleaning systems. In light information contained in these alteration layers and deposits has of that work, Institute staff invited been understood only recently, and it is more appreciated every day. the heads of three Getty Museum Because of earlier, certainly more aggressive cleaning techniques, conservation departments to sit we’ve lost a great deal of that information for a lot of sculpture down together to discuss some of the in collections around the world. But our field has changed philosophical and technical issues considerably in the last several decades. The degree of cleaning has related to the surface cleaning been reduced dramatically, and cleaning is approached with much of objects in museum collections. more caution now. What survives on the surface of the object is Participating in the roundtable highly valued—and that now includes the historic information discussion were Brian Considine offered by artificial patinas applied to ancient sculpture in the th of Decorative Arts and Sculpture and th centuries. Conservation, Mark Leonard of Narayan Khandekar: Jerry, the layers that you are trying to Paintings Conservation, and protect are not necessarily man-made or part of the creation Jerry Podany of Antiquities of the object. They have accrued over a period of time. Conservation. Joining them in the discussion were Alberto de Jerry Podany: Generally speaking, there are three categories of Tagle, chief scientist at the GCI, patina. One is an alteration layer that occurs due to accidental or Narayan Khandekar, a GCI natural change—during burial or weathering, for example. Another associate scientist, and Jeffrey is an intentional coating, perhaps ancient or perhaps applied at a Levin, the editor of Conservation. much later date as part of a restoration or later use. Finally, there

10 Conservation, The GCI Newsletter lVolume 15, Number 3 2000 lDialogue are those changes or accretions that occur as indirect results of other intentional actions—rust stains from metal attachments, or obscuring stains from restoration materials that proved unstable over time. It can be quite complex and rather subjective to deter- mine which of these categories have value, alone or in combination with others. Narayan Khandekar: The idea of patina in the paintings field begins Pam Posey with the assumption that something from the underlying paint layers has penetrated into the varnish, changing the appearance of the top layer. Does that idea of patina carry across to decora- tive arts as well? Brian Considine: Very definitely. The structure of the surfaces we deal with doesn’t differ significantly from paintings in many cases. Whether they are oil paint layers or different types of coloring agents suspended in a binder, it’s really the same type of system. But there are also some major differences. Terracotta surfaces, for example, can be very difficult to clean because of their porosity and because many have an original surface slip that is very lean in binder.

Maya Elston Jerry Podany: I’d like to ask Mark to comment on controversies in the cleaning of paintings. Some controversies that have erupted around sculpture ultimately have been quite healthy for our field— the recent controversy regarding the overcleaning of some of the Parthenon sculptures in the British Museum, for example, or the severe criticism of restorers and conservators by Professor Beck with respect to the justification of cleaning a number of sculptures. These criticisms from outside the field have, I think, encouraged us to look more closely at our own motivations and reasoning. Every- one—conservator, scholar, art historian, connoisseur, director, curator—is investigating more carefully why we undertake restora- tion and if those reasons remain valid. These controversies have had an enormous effect on sculpture conservation—and I think a Ed Carreón positive one. What about paintings conservation? Mark Leonard: Everything we do in conservation is geared to be reversible, but the one thing that is irreversible is cleaning. So it is the most critical conservation activity. Anything that makes us question what we are doing and why we are doing it drives our field to have a deeper understanding of the materials that we are working with. It is a good thing, even if the process is painful and annoying. Narayan Khandekar: I have a slightly jaundiced view of cleaning controversies as related to paintings. I think they’re inevitable. They have forced conservators to look at their craft, but I’m not sure how much they’ve directly advanced the cleaning of paint- ings. I don’t know if they’ve had any other outcome except that of prompting certain outspoken members of the viewing public— who appreciate a painting in a certain state—to say that they don’t like the change.

Conservation, The GCI Newsletter lVolume 15, Number 3 2000 lDialogue 11 Brian Considine: I have to disagree. I support Mark and Jerry’s point Mark Leonard: I think a little. Fifteen years ago, we rarely saw poten- of view that any controversy really causes us to question what we tial acquisitions that hadn’t been cleaned, but we were quite vocal are doing and why we are doing it. I don’t think we can ever do too about saying that we wanted to be shown pictures that had not been much of that. In my department, for example, I sometimes play touched. The Getty certainly wasn’t the beacon in the field—this devil’s advocate when we are talking about a treatment, because was true for most museums. Now I rarely see a picture that has been there is tremendous benefit in really having to articulate your rea- touched. They are usually left alone, and the same is true of pic- sons for decisions regarding a treatment. tures sold at Sotheby’s and Christie’s. I think that once it gets into Mark Leonard: I think we are getting better at dealing with contro- the broader market, the more expensive the picture, the better fi versies and with the specific issues in a more intelligent fashion. I’m chance it has of nding its way to a good conservator and receiving thinking specifically about the collaborative restoration project we proper care. On the less expensive side, things that are kind of ff ff have with the Yale University Art Gallery on early Italian paintings, cranked through take on a very di erent look and a very di erent and the work that Narayan has done to identify some original sur- treatment in that process. There is a lot of room for improvement, face coatings that have miraculously survived in a few cases. It has but I think we have come a long way. given us a much stronger foundation upon which to address issues Alberto de Tagle: One problem is that we don’t have a clear defini- of our own cleaning and polemics in the past. I hope that kind of tion of cleaning. thing will increase. We’re still at the frontier of understanding the Narayan Khandekar: In the late s, Gerry Hedley defined three issues of original surfaces in paintings, but I think we are very far levels of cleaning for paintings: partial, complete, and selective.  along in valuing those materials. That wasn’t true years ago. Do you think the field has moved on from that? Brian Considine: I have to say that one of the last bastions where Mark Leonard: Yes, we have moved beyond that a bit. In this country we see an awful lot of damage—and it’s really heartbreaking—is at least, I think there is a general consensus about aesthetic consid- decorative arts in the marketplace. Furniture, in particular, is auto- erations and degrees of cleaning, and certainly a deeper under- matically stripped, and mounts are regilded. It’s completely aes- standing about what we are cleaning away, as well as the materials thetically driven; there is some kind of agreement in the market- that we are using to do it. fi  place about how a very ne piece of th-century French furniture I worry, however, that the pendulum is swinging just a bit too fi should look, and any sacri ce is made to make the object look that far. The more we begin to understand the value of original surfaces, way. It’s common practice for marquetry to be embellished by what can happen—and I’ve seen this in various museums—is that adding detail that was not originally there; for Boulle marquetry to a kind of paralysis sets in, where you become so terrified of doing be re-engraved; and for painted objects to be stripped and gilded anything that you wind up doing nothing. That may be good in the instead of painted, because they are worth more in that condition. short run, and generally no harm comes from doing nothing, but Jerry Podany: The desire for a perfect object—and the existence of I hope that as a field we are beginning to find a certain balance restorers who will provide one—has caused damage to antiquities between doing nothing and doing something. for centuries. I’ve seen really wonderful objects ruined for the sake Brian Considine: I’d like to follow up on Mark’s comment about the of a brightly polished surface or a pristine form. But the problems pendulum swinging. At the risk of sounding like the enfant terrible, aren’t isolated to the fashions of the market. We have our own I think there is a lot of talk about removing an original surface. If ff museum fashions a ecting conservation and the objects. There are you take furniture as a case in point, sometimes there are very good many large collections of Greek and Roman objects that have had reasons to remove an original finish. These are resin coatings that little maintenance or treatment in many years and that are now, have a certain life span, and if a table has been subjected to light for suddenly, getting a great deal of attention. To be on the “cutting  years and the finish is completely crazed and degraded, it is no edge of conservation,” some museums are subjecting their collec- longer serving its purpose. You can argue that the finish is actually tions to fairly severe cleaning campaigns, often removing earlier obscuring the aesthetic message rather than being part of it. restorations with little consideration of the value of what is being Jeffrey Levin: So when you remove that surface, you are improving removed. As a result, we’re losing a lot of historically important access to information about the object or to part of its history? information about the attitudes of the last  years and about the history of restoration. Brian Considine: Yes. Jeffrey Levin: Mark, would you say that the paintings market is Jeffrey Levin: That’s a choice you make. farther along in this regard? Brian Considine: I’m not saying I would always make it, but it is something to consider.

12 Conservation, The GCI Newsletter lVolume 15, Number 3 2000 lDialogue —Mark Leonard

Alberto de Tagle: Brian, I think you are saying that it depends on Jerry Podany: Yes, you’re right. But in this case there is a great the kind of object, the type of collection, and the message you are difference in what we can assume about the original appearance seeking. Would the approach be the same for an archaeological of the object. We have so little direct information about antiquities, object from antiquity? whereas the closer one gets in time and culture to an object, the Jerry Podany: It’s different for ancient works. Anything that remains more readily one understands its original intent and form. as part of the original surface is valued as irreplaceable. The prob- Brian Considine: I guess I’m referring to the difference in the aes- lem is identifying what may be evidence of an ancient decorative or thetic standards for restoration and those for archaeological treat- use-related coating or surface. The effort to do that and the results ments. We would not repair a loss in a terracotta vase with a plain fill have significant implications in our cleaning decisions. that was very noticeable. Brian Considine: The point is also that here at the Getty, we are in an Mark Leonard: I’d like to return to the issue of “patina,” which is a incredibly privileged situation. The majority of people working on word I don’t use in paintings conservation, and one that paintings furniture have no access to a microscope. conservators as a whole seldom use. There’s an important distinc- Jerry Podany: I think you’re getting to a very important complexity tion. I do talk about the original skin of the picture but patina that we should recognize when we talk about what is and is not implies something more complex, and I think it is more suited to cleaned away. For example, let’s consider ancient bronzes—and three-dimensional works of art. only Roman bronzes. Depending on whether that bronze is in an As a paintings conservator, I don’t think I could return an old archaeological museum, an anthropological museum, a study collec- picture to what the artist’s original intent was. The materials them- tion, or a fine arts museum, it may well look entirely different selves have changed so dramatically over time, and I can never turn because the cleaning approach taken was a direct result of the the clock back to make it look the way it did when it left the artist’s philosophy and assumptions of that particular type of institution. studio. All I can do is work with the changed materials, make some If you then compare a Roman bronze and a Chinese bronze in the sense of them, and let them speak in some meaningful way. And fi same institution, the two objects are often treated completely differ- when I nd a painting that we think still has its original “skin” or ently. Somehow it’s okay to remove what is still termed the “vile” surface coating, I work within the parameters of that existing sur- patina on a Roman bronze, reducing the surface to a smooth and face—but I accept the vast changes that have taken place under- shiny facade that is completely foreign to the corrosion and cen- neath that skin. The pigments have faded in some areas, but not in turies it has experienced. But that type of treatment is rarely carried others. Some areas have become transparent and dull. Other areas out on Asian bronzes, because of some romantic idea associated have retained their original intensity. That complete shift in balance with the exotic and the assumed philosophical appreciation of nat- is what I’m playing with in the cleaning process. ural processes. While there may be some truth in this, it is mostly a Jeffrey Levin: One of the general impressions I’m getting is that as contradiction and an ill-founded practice. While I agree with Mark conservation has matured, and as it attracts more public atten- and Brian that it varies object by object, I also think we have yet to tion, in an ironic way there appears to be at least the beginning identify these contradictions within types of collections and institu- of a shift toward less treatment. Conservation seems to have tions that directly affect the object. become as much an intellectual and philosophical activity— Brian Considine: Consider how you treat terracotta in the Antiquities in terms of evaluating what you’re not going to do, as opposed to Department and how we treat terracottas. It’s totally different. what you may do. Is that correct?

Conservation, The GCI Newsletter lVolume 15, Number 3 2000 lDialogue 13 Mark Leonard: It is certainly true in the general sense. But there is any responsibility. I think, as a field, we understand that now— still a lot to be done. I hope we are far more thoughtful about why perhaps more so than  years ago. we’re doing what we’re doing—and slower in actually doing it. It’s Brian Considine: I think there used to be this concept that you could not unusual for us to have a new acquisition sit in the studio for two do something to a work of art and avoid a personal aesthetic judg- to three months before we do anything, just because it takes that ment. I strongly believe that is not possible. Even the decision to do much time to get to know the object. something is based on aesthetics in many cases. Even the lightest Jeffrey Levin: Is it correct to say that  years ago some of the cleaning, dusting, or vacuuming involves an aesthetic intervention. questions you are raising now would not even have been raised? Mark Leonard: Anything you do that changes the look of the work Jerry Podany: Some of the questions were raised  years ago, but of art changes the meaning. That can be from the simplest inter- they just hadn’t filtered their way throughout the field. Change in vention, as Brian described, to a more radical policy. conservation takes a long time. Whether that change is for the bet- Brian Considine: It’s a personal aesthetic judgment that you’re ter or worse, it’s good to move slowly. We are much more deliberate making. It can’t be impersonalized. today in what we do. We spend a lot more time in introspection, Alberto de Tagle: Can we talk about the process by which decisions because of past lessons and because our responsibilities are broader are made as to what should or should not be cleaned? Are there than they used to be. The more we find out about the potential differences in each of your departments in how those determina- impact of what we are doing, the more responsibility it carries with tions are made? it. It doesn’t mean that we freeze in our tracks. It just slows us ff down, and we act more responsibly. Brian Considine: I would start o by saying that there are at least two So in some ways you’re right. But to interpret that as meaning reasons to clean something. Certainly the most pressing one would that our whole job is philosophical—no, as Mark said, there’s be if there was the conviction that a coating was actually detrimen- plenty to do. The implications of the ethical and philosophical tal to the object. That obviously would carry some urgency. The issues that have been brought to bear on what we do are that now other reason is the more obvious one—for an aesthetic change. In nothing is done as a matter of course anymore. Now we look more that case, we would discuss with the curator the fact that an object’s carefully at each individual case. current appearance was a very inaccurate representation of the artist’s intent—that the viewer was being distracted by the dirt or Jeffrey Levin: And the other thing is that in some sense it may take that it was really falsifying the aesthetic message of the object. longer to do less. That’s more of an optional intervention. In those cases, the conser- Brian Considine: Absolutely. I also feel that one of the most exciting vators take the lead by researching the material aspects of the aspects of conservation now is trying to contribute to the history of object, learning as much about the artist’s work from the curator, art through technical studies of the objects, the materials, and the and gathering information about comparable materials. We would manufacturing processes, the processes of alteration, and the accu- also possibly research comparable treatments, either within the mulation of subsequent surface coatings or grime. department or further afield. We would work with a conservation Jeffrey Levin: How new is this concept of conserving the surface scientist to analyze cross sections or carry out different material because it provides information? analyses of the layers in question, and investigate to see if there is a Jerry Podany: I think it differs from field to field. You can find very cleaning system that would enable us to achieve our aesthetic goals. early examples. The first reference to the beauty of white marble It’s really a three-cornered collaboration that involves a lot of is in the medieval period. By the th century, they were stripping exchange of opinions and information. everything in sight to reveal that beauty at the expense of seeing Jerry Podany: In the antiquities field, the amount of information evidence for polychromy. But even then there were those who that we now know has been or is still lost through inappropriate warned about the loss. It’s an ongoing debate. The scale keeps cleaning—ranging from traces of pigment and decorative coatings tipping. Right now, conservators are tipping toward caution and all the way to whatever remnant of binder might still be there— toward avoiding mistakes. is very sobering to the field. Conservators of artifacts and ethno- Mark Leonard: One thing that comes up over and over again in graphic material are intensely aware of the kind of damage and loss cleaning controversies is scientific objectivity. I think a lot of con- that can occur. At the Getty Museum several decades ago, curators servation in the past was done in the name of scientific objectivity, held enormous sway over what was cleaned and how extensively it when in fact, what we were really doing was absolving ourselves of was cleaned. The conservator has always made the decision if whatever was being removed was dangerous to the object, as Brian

14 Conservation, The GCI Newsletter lVolume 15, Number 3 2000 lDialogue mentioned. But if it wasn’t a direct threat, then it was almost exhibitions and by helping the public understand what materials always an aesthetic decision made by the curator. That has changed these objects are made from and what has happened to them. fi signi cantly. Alberto de Tagle: In the last  years, we’ve seen significant We now realize how valuable some of these deposits can be. changes in the technical aspects of surface cleaning. Besides Even if we’re trying to target grime that has very little, if any, value, lasers, one of the most controversial cleaning techniques has been the action of cleaning may result in the loss of evidence that is there the gel systems—often referred to as the Wolbers methods. Can from antiquity or from some other cultural or historical context. you talk about how these methods have contributed to surface For example, now there is always a very long waiting period before cleaning approaches? we begin to clean. The object may go on exhibition for a long time Mark Leonard: I’ll start with what was a kind of epiphany for me, before we undertake cleaning. It gives us time to consider the which is a slide that Richard Wolbers showed during his first lecture action and the potential results. I would say that over the last  as a Getty Museum Guest Conservator in . It was a cross sec- years, a great number of the objects that were targeted for cleaning tion of a layer of shellac from a piece of furniture that had been didn’t get cleaned because, over time, discussions brought to light French-polished. The shellac had been applied with repeated rub- the fact that there was no benefit in cleaning them, that removing bing as part of the manual application. The cross section showed the encrustation or some disfiguring dirt would not really benefit that the natural oil in the wood had been drawn up into the French the object. polish layer. Then we have those cases where cleaning is simply not In that single shot, Richard captured what many paintings possible technically, at least at this moment. We have a number conservators had been talking about for many years—the idea that of objects that we know have brilliant painted designs underneath the intimacy of the bond between the varnish coating and the oil the encrustation, but the pigment is more tenaciously attached paint underneath is much more complex than we have been able to to the encrustation than to the terracotta, and so they’re left alone quantify. Richard took some very important steps toward quantify- for now. Your question is a good one, and I think our field is ing the intimacy of those bonds and was able to begin thinking changing dramatically. about putting solvents into gel form to specifically target the kinds Brian Considine: Part of the reason that it has changed here is of surface coatings that he was able to identify. because of our administrative setup, where we have equal access to Jeffrey Levin: Mark, that epiphany—that recognition of the the director. In many museums, the conservators report directly complex relationship of layers of material—is it something to the curators, so they can have difficulty in not following the that is now generally shared in the field? curator’s instructions. In some European countries, the situation is more difficult because much of the conservation of museum Mark Leonard: I think it’s increasingly understood. I wouldn’t say objects is done by freelance conservators who, in an ethical dis- that it’s shared as much as it should be. There’s an intuition on the agreement, possibly face alienating themselves from future work part of many conservators that cleaning is not simply a matter of at that institution. removing a surface coating from a substrate. It would be very sim- ple to think of removing a varnish from a painting as an on-or-off Mark Leonard: I think it’s a little different in paintings conservation. proposition. But in fact, the relationship between the varnish and Let me backtrack a bit to answer your question as to how we go the paint goes across infinite shades of gray. You never reach a point about deciding on whether to clean a painting. At the Getty, we do where the varnish is all off and only the paint film remains. The operate in an ideal world with regard to our relationship to the bond that you’re dealing with is so intimate—as was demonstrated administration and to the curatorial departments, and in our influ- by the slide of that French-polished cross section. The area where ence over the care and appearance of the collection. In all respects, the oil extruded into the varnish and the varnish penetrated into the I use as my underlying philosophy, “let the work of art be your wood is this very gray region that I don’t think we completely guide.” So the painting is, in fact, the source for determining what understand. Richard Wolbers provided a more scientific foundation needs to be done to it. That works very well when you have a knowl- for that intuitive concept that has been refined with the work that edgeable group of conservators, curators, and conservation scien- the Getty research team and others elsewhere are doing. But we tists who can all talk to one another in a common language and with have a long way to go. a common purpose. I think the field has matured to the point where conservators really do play as vital a role as curators in the life of the museum, and we can play an increasingly public role by being involved in

Conservation, The GCI Newsletter lVolume 15, Number 3 2000 lDialogue 15 o

News in Conservation the gel’s contact with the surface to be cleaned. Any tobe cleaned. the gel’s withthe surface number contact of water, improves agent—which athickening andasurfactant—also of withthe addition thickens apolymerresin that base composedof Delaware. systemshave Thecleaning anaqueousgel University of the community by Richard Wolbersduced totheconservation of 16 cellulose-based materials. pulp, waxes, clays, andvarioustypesof objectshave agents, paper usedthickening including of servators paintingshave usedwax-solvent pastes, whilecon- of Conservators e particular,provide morecontrol—in by slowing thesolvent’s techniques solutions. With thelasttwo methods, anumber of solvents oralkali-basedaqueous organic with scalpelsortheuseof p. Cleaning,” aboutSurface Balance:ADiscussion a Certain aswell (see“Finding thereareethicalones considerations, technical original decorativelayers areremoved. toaestheticand Inaddition canalsopresent di terracotta, withporousorunpaintedsurfaces, asmarble such Artifacts or sired layers canberemoved tounderlying ones. withoutdamage process, inthecleaning unde- control sothat deal of allows agreat amethodthat layers. of selection Technical include considerations and/oroverpaint orothercoatings varnish or completeremoval of view, have partial decisions tobemaderegarding aesthetic pointof monuments. rials—and of aspaintings,objects—such decorativearts, mate- orarchaeological museum of cleaning isthesurface treatment conservation of O By Valerie Dorge Research Project The vaporation rate or reducing its migration to surrounding areas. tosurrounding orreducingitsmigration rate vaporation   In theearly Tr P ainted surfaces especiallypresentdi ainted surfaces aditional cleaning methods include mechanical removal mechanical methodsinclude cleaning aditional Conservation, TheGCINewsletter  Gels s,

alternative cleaning systemswere cleaning intro- alternative ffi l and sometimes controversial stages and sometimescontroversial culties whengrime,stains, ornon- V olume 15 , Number ffi 3 culties. From an 2000 l News inConservation Cleaning  ). on information hasin-depth improvedfurther whentheconservator prepared forprepared speci over process. control thecleaning conservator’s Thesystemscanbe like-dissolves-like). theprincipleof andtheywork on varnish, the (theresinsoapshave of similartothat varnishes achemistry c orundesiredpaintlayer, dissolvethat thevarnish enzymesthat c meiett oewdsra s fsolvent-based gels. impediment tomorewidespread useof residuehave regarding notbeenfullyansweredtions andremainan thespeci However, becauseof e possible long-term aspects of ra ing thepaint’s chemistry, thereby itsdeterio- possibly accelerating thepaintoralter- would increasingthesolubilityof dangers include surfaces— theresiduemightposeadangertosurface. These treated the so, if on left and, if is gels the of residue any not or whether c e long-term thepossible scientistsregarding andconservation conservators labpractice. intoconservation widely incorporated advantages, theseimportant thenew systemshave cleaning been of exposuretovolatile toxic chemicals.conservator’s Because organic paint layer toberemoved. theysigni Inaddition, thecoating, or dirt, of thenature andon paint-layer stratigraphy; hemically breakdown oils, remove andresinsoapsthat degraded canbeadded tothisgelbase.leaning agents solvents Theseinclude leaning with these systems. The most pressing concern hasbeen leaning withthesesystems. Themostpressingconcern in ubro ntttoshv netknsuiso various have institutions studiesof undertaken Anumbertion. of

the chemical composition of the surface to be cleaned; on the on tobecleaned; thesurface of composition the chemical h hmclcmoiino thesesystemsincreases the of composition The chemical Nevertheless, a number of concerns have by beenraised some concerns Nevertheless, anumber of ff ects on surfaces, paintedsurfaces,ects on particularly of fi c cleaning tasks.c cleaning Theire fi ff ou fthesestudies, theques- c focus of csfo s fthegelssystems. ects fromuseof Photo: for possiblesurfaceresidue. later. Thesamplewillbeanalyzed of theEnsorpainting12years minute samplefromthesurface Narayan Khandekarremovinga Bottom: (1889). Christ’s EntryintoBrussels the JamesEnsorpainting cleaning processin1988on Getty Museum,usingthegels of PaintingsConservationatthe T op: ff ectiveness canbe Mark Leonard,head Photo: Dusan Stulik. fi GCI associatescientist cantly reducethe Elisabeth Mention. The Gels Cleaning Research Project

To provide the conservation community with definitive answers on “the residue question,” the  incorporated research on this sub- ject into a broad  scientific research project on surface cleaning, begun in . The  gels project is in collaboration with the Analytical Laboratory of the Winterthur Museum, Garden, and Library, the Winterthur–University of Delaware Program in Art Conservation, and the Department of Chemistry, California State University, Northridge (). The Getty research team includes scientists and conservators from the  and the Getty Museum. At the start of the project, three main research areas were identified: () quantitative measurement of gel component residues; () aging characteristics of the surfactant components and investigation of the interaction between gel residue and paint layers; and () analysis of the surface of paintings cleaned during the past  years with the gels systems. In the course of research, a fourth subject was added: a study of solvent residue left on and in paint layers following traditional cleaning with only solvents or solvent mixtures. To measure the amount of residue left after use of the gels systems, the project team developed a highly sensitive methodology that uses radioactive materials to label the gel components. Four chemically identical gel formulations were used, each with one major component labeled. This methodology was applied to a cleaning experiment carried out in November  at . An international group of conservators and conservation scientists participated in the experiment (see Conservation, vol. , no. ). The preliminary results of this study, which is nearly com- plete, were presented to the conservation community at the biennial congress of the International Institute for Conservation of Historic and Artistic Works (), which took place in Melbourne, Australia, in October . The study showed that there was very little gel residue left on the cleaned test surfaces. To put this finding into perspective, the quantities were equivalent to the average amount of material transferred to a surface by touching it up to  times with a finger. The results of this study will contribute to develop- ment of parameters for an optimal cleaning procedure. Current work focuses on identification of decomposition products of the gel surfactants that have been found to be unstable under ultraviolet irradiation. This study is performed with the aid of a residual gas analyzer, which identifies gaseous molecules that are generated during exposure of the gel residue to ultraviolet light. Interaction of the residue with the paint film will be studied as well. Sample films of the four most common types of paint surfaces— casein, egg tempera, distemper, oil—will be subjected to cycles of cleaning, varnishing, and aging. The study will attempt to deter- mine if gel residue is encapsulated during the revarnishing process

Conservation, The GCI Newsletter lVolume 15, Number 3 2000 lNews in Conservation 17 and, if so, whether it is removed in a subsequent cleaning. Surface already completed work measuring the amount of gel component distribution of the gel residue will be studied through two-dimen- residues, the artificial aging tests are being repeated, with sampling sional autoradiography—a technique that locates the distribution of at shorter time intervals. Preliminary results indicate that the the gel residue in a sample—in combination with laser profilometry, surfactants degrade rather quickly. These studies will provide con- which measures the topographical features of the cleaned sample servators with the necessary information to help them select an surface. To date, this study has concentrated on the potential appropriate surfactant for a gel formulation. residue on a representative painting—fragments from a large  In a complementary accelerated aging test at the , a quan- painting on canvas by Frank Linton that had been vandalized and tity of cleaning gel containing the surfactant Ethomeen was applied subsequently donated to the Winterthur–University of Delaware to a sample; half of the sample was then covered with aluminum Program in Art Conservation. foil, and the full sample was exposed to ultraviolet radiation. The Because the gels cleaning systems are widely used for cleaning amount of radioactivity decreased tenfold during the eight-week painted or unpainted objects, the question of gel residue is also test period of continuous exposure. This indicates that the applicable for these materials. Therefore, the existence of residue Ethomeen is prone to decomposition by ultraviolet radiation and and its potential long-term effect for this class of objects is now that some low-molecular products of the decomposition process being studied. As a first stage, four materials have been identified by evaporate from the irradiated paint surface. This interesting finding the conservators in the Decorative Arts and the Antiquities depart- confirms the Winterthur experiments and will help to further the ments of the Getty Museum. These materials—gilded wood, understanding of what happens to Ethomeen when it is left on the unglazed terracotta, marble, and plaster—are representative of sur- paint surface after cleaning. Further work on Ethomeen residues faces commonly found on museum objects. They will be subjected remains to be done. to a cleaning experiment similar to that carried out on the test The third part of the project will involve analysis of the sur- painting samples. Modification of the methodology developed for face of paintings cleaned with gels systems during the past  years. the initial experiment, especially with regards to sample prepara- Because these systems were first used in the mid-s on museum tion, posed a challenge for the project team. The characteristics artifacts, analysis of the surfaces of some of these artifacts provides of these materials—for example, the hardness of the marble and the the potential for determining if any optical or chemical change has friability of the terracotta—made separation of individual samples taken place on or within the surface layers over time. It is hoped that from the prepared panels much more difficult than for the painted the project’s analyses can identify the source of any such degrada- canvas samples. (Separation is needed, as each sample is placed in tion as a way to determine if the degradation can be linked to a small vial that is then inserted into a scintillation counter that residue from the gel cleaning components. measures the radioactively labeled components of the residue.) The two main components of any residue will be the surfac- After a number of ways were tried to separate out the samples, sep- tant Ethomeen and the gelling resin Carbopol. Investigation of a aration was achieved by scoring (within a millimeter of the surface) potential analytical method to detect Carbopol in the residue on the the underside of the sample before cleaning. surface of paint samples was successful for a model situation in which a large amount of sample was available. However, it was not

Other Studies in the Project successful for the small amount of sample that could be taken from a museum object. Therefore, Ethomeen now is being investigated as Although the chemical properties of surfactants are known, their a marker for detecting residue, as the available analytical methods long-term stability under natural and artificial aging conditions has can identify it more easily. Analysis of samples collected from not been studied. For that reason, two parallel studies are being car- objects treated with gels over the last  years is just beginning. The ried out in the Analytical Laboratory of the Winterthur Museum, samples were taken from seven th- and th-century paintings Garden, and Library, to evaluate the deterioration products of a and decorative art objects. number of surfactants used in surface cleaning on representative The ongoing studies of gel residue being conducted will films, including a linseed oil film. provide an insight into the amount and chemical composition of To date, the films have been analyzed at -hour cycles of residue left on the surfaces of objects following gel cleaning. The artificial aging—which represent  to  years of normal museum fourth part of the project will compare these residues with possible lighting conditions—to identify the degradation process. The rate residues left by traditional solvent-cleaning methods. A series of of change of the nonvolatile surfactants to more volatile degrada- experiments is being performed to provide information on any tion products is currently being examined. Based on the project’s solvent residue in the paint layers following solvent cleaning. The

18 Conservation, The GCI Newsletter lVolume 15, Number 3 2000 lNews in Conservation Left: GCI project team members Herant Members of the Gels Cleaning Khanjian and Valerie Dorge installing the Research Project Team prepared paint films in the Atlas Weather- Ometer in the GCI scientific laboratories. The films were subjected to 12 weeks of Getty Conservation Institute artificial aging, simulating a museum environment. Photo: Dusan Stulik. Valerie Dorge Nora Ibarra Narayan Khandekar Herant Khanjian Dusan Stulik Alberto de Tagle

J. Paul Getty Museum Right: Brian Considine (right), Getty Museum decorative arts conserva- Brian Considine, Decorative Arts tor, and David Miller (left), professor Conservation of chemistry at California State University, Northridge (CSUN), con- Joe Godla, Decorative Arts Conservation ducting a cleaning experiment on a Mark Leonard, Paintings Conservation gilded wood sample in the CSUN chemistry laboratory. The objective Jeff Maish, Antiquities Conservation of the experiment is to determine the amount of residue left on the gilded Eduardo Sanchez, Antiquities surface after the gels cleaning Conservation process. Photo: Valerie Dorge. Yvonne Szafran, Paintings Conservation solvents selected are those most frequently used in conservation Winterthur Museum practice today in the United States and in Europe: acetone, benzyl Janice Carlson, Analytical Laboratory alcohol, dimethylformamide, dodecane, ethanol, isopropanol, W. Christian Petersen methanol, N-butylamine, toluene, and xylene. This study also Winterthur–University of Delaware includes an investigation of the potential for even the highest- Program in Art Conservation purity grades of organic solvents to introduce to the cleaned paint Richard Wolbers layer impurities that may not evaporate and which, therefore, may California State University, Northridge contribute to any degradation of the paint layer. David Miller, Department An important objective of the gels cleaning research project is of Chemistry to make the results of its studies available to the conservation com- munity. In addition, the project seeks to provide conservators with some recommendations to help them prepare gel formulations that Components will be the most effective in the cleaning process or in removing of Gels Cleaning Systems layers—while minimizing the risk of future damage to surfaces through degradation from residue or other chemical reactions. The gels cleaning systems have an aqueous As already noted, the preliminary results from the quantifica- gel base that includes a polymer resin and a surfactant. The surfactant is usually tion of gel residue were presented at the  Congress in Mel- Ethomeen (an ethoxylated [] coco- bourne. Other dissemination efforts are under way. An article alkylamine), and the water-based resin is entitled “A Survey of the Conservation Literature Relating to the usually Carbopol, a polyacrylic acid.

Development of Aqueous Gel Cleaning on Painted and Varnished To this gel base, any number of cleaning Surfaces” by project team member Narayan Khandekar will appear solvents can be added. The most common this year in volume  of Reviews in Conservation, a peer-reviewed solvents used in the solvent-based gel formulations include acetone, isopropanol, journal published by the . A full report on the project—includ- ethanol, toluene, xylene, and benzyl ing the methodology developed for the experiments, the data alcohol, or mixtures thereof. obtained, the conclusions reached, and the pertinent recommenda- tions—will be published by the .

Valerie Dorge is a project specialist with the GCI. Other members of the gels cleaning project assisted in the preparation of this article.

Conservation, The GCI Newsletter lVolume 15, Number 3 2000 lNews in Conservation 19 P v n by Aleksey Gibsonreser and Jane Siena Talley atio in

A    S. P prepares for its th birthday in , the St. Petersburg International Center for Preservation is assuming an increasingly vital role as the only noncommercial organization devoted exclusively to cultural heritage preservation Ain this World Heritage City and former capital of Russia. The Center for Preservation has grown from a modest part- nership of three founding organizations—the Russian Academy of Sciences, the city of St. Petersburg, and the Getty Conservation Institute—into an independent organization backed by a strong coalition of over  cultural institutions in St. Petersburg and a range of museums and libraries in the United States and Europe. The Center’s mission is to encourage and facilitate modern conser- vation strategies, such as preventive care of collections, through professional programs in education and training, information services, collaborative scientific research, and heritage advocacy. At first temporarily headquartered in the Lavalle Palace, the Center moved into its permanent home in the historic Trubetskoy- Naryshkin Mansion on Tchaikovsky Street in June . It is scheduled to open its new Nicolaas Witsen Information Facility by the end of . Since last reported in this publication (see Conservation, vol. , no. ), the Center has reached a number of significant milestones in its establishment as a permanent center for the preservation of the cultural heritage of St. Petersburg and the surrounding region.

Programs and Resources

Top: The exterior of the historic Trubetskoy-Naryshkin Mansion, now the permanent Conceived in the aftermath of the disastrous  fire at the home of the St. Petersburg International Center for Preservation. Photo: Sarah Gore. Library of the Russian Academy of Sciences, the Center seeks to

Bottom: An interior view of the imperial palace of Peterhof, site of the Center’s implement programs that address the enormous conservation October 2000 seminar on controlling crowds. Photo: Sarah Gore. needs of cultural institutions in St. Petersburg. Ranging from well-known museums and palace complexes, such as the State

20 Conservation, The GCI Newsletter lVolume 15, Number 3 2000 lNews in Conservation St. Petersburg

Hermitage Museum, the State Russian Museum, and the summer Advisory Council of the Leaders of Recent palaces of Tsarskoe Selo and Pavlovsk, to other kinds of institu- St. Petersburg Seminars tions, including the National Library, the Academy of Sciences, the International Center and Workshops for Preservation Oriental Institute, and the Mariinsky Theater, these repositories Gordon Anson, Chief share similar concerns. Among these concerns are security matters Dr. Mikhail Shvydkoy, Minister of Production, Design Department, of Culture, Russian Federation National Gallery of Art, (ranging from crowd control to theft and terrorism); disaster pre- Washington, D.C. paredness; pollution and environmental degradation; fire and Dr. Mikhail B. Piotrovski, flooding; and collections management and staff training. Director, State Hermitage Museum Oleg Boev, Head of Security, State Hermitage Museum To provide Russian curators and conservation professionals Dr. Vladimir A. Gusev, Director, access to the wealth of knowledge available worldwide in the field State Russian Museum Marilyn Dunn, Conservator, Cornwall Regional Office, of conservation, the Center organizes seminars, symposia, work- Dr. Vadim V. Znamenov, National Trust, U.K. shops, and consultancies. These activities not only serve a didactic Director, State Peterhof Museum Wilbur Faulk, Senior Project purpose but also create a forum in which conservation professionals Dr. Valerii P. Leonov, Director, Manager, Getty Conservation can learn from one another in a collegial environment. Library of the Russian Academy Institute During the – academic year, the Center hosted a of Sciences Ivan Karlov, Deputy Director and number of seminars and workshops in response to the requests of Dr. Vladimir N. Zaitsev, Director, Chief Curator, State Russian its constituents in St. Petersburg. These included an April  Russian National Library Museum seminar entitled “Preventive Conservation: Improved Exhibition Dr. Alexander D. Margolis, Catherine MacCarthy, Procedures,” led by experts from the State Russian Museum, the Director, International Foundation Conservator, Severn Regional Office, for the Salvation of St. Petersburg State Hermitage Museum, and the National Gallery of Art in National Trust, U.K. Washington, D.C. The seminar addressed exhibition planning from Dr. Rudi Ekkart, Director, The Viktor Pavlov, Head of Design, the viewpoints of aesthetics, conservation, and protection of works Netherlands Institute for Art History Design Department, State Hermitage of art. Two months later, conservators from the National Trust in Dr. M. Kirby Talley Jr., Museum ff the United Kingdom, in partnership with sta of Pavlovsk Palace Executive Counselor for Caroline Rendell, Conservator, Museum, led a seminar entitled “Good Housekeeping in Historic International Cultural Heritage Northumbria Regional Office, Policy, Netherlands Ministry of Collections,” sharing their considerable expertise in the cleaning National Trust, U.K. of historic objects and interiors with colleagues from the various Education, Culture, and Science Founding Director, St. Petersburg Mervin Richard, Deputy Chief palace museums and collections in and around St. Petersburg. International Center in St. of Conservation, National Gallery As part of its ongoing series on security, the Center also Petersburg of Art, Washington, D.C. sponsored, in collaboration with the Russian State Security Bureau Nikolai Tretiakov, Director,    ( ), “Security Seminar ” in June , led by security experts Pavlovsk Palace Museum from the Getty Trust, the Hermitage, and . This seminar was Brent Woodworth, Manager, devoted to crisis management, disaster preparedness, the  prob- Global IBM Crisis Response Team

Conservation, The GCI Newsletter lVolume 15, Number 3 2000 lNews in Conservation 21 lem, and cultural terrorism. Following the seminar, the , in St. Petersburg professionals, including one to present a paper at an response to the recent wave of bombings in Russia, approached the Oxford University symposium and another to study historic foun- Center with a request to hold a seminar on heritage terrorism. This tain design and maintenance in Spain and Italy. seminar focused on the potential threat to cultural institutions. In tandem with its educational and scientific programs, the “Security Seminar ,” in October , was devoted to the prob- Center sees itself as an advocate for heritage preservation through- lems of crowd control, particularly at the highly popular summer out St. Petersburg. In order to raise awareness of the conservation palace of Peterhof. needs of the city and its region, the Center seeks to build partner- Future programs in planning include seminars and intern- ships with Russian government bodies and other like-minded ships devoted to textile conservation and historic costumes, musical organizations, such as Save Venice. The Center also promotes instrument conservation, and, in collaboration with the Mariinsky preservation through publications, public lectures, videos, and Theater, the restoration of rare th-century musical scores by Ital- exhibitions. For example, the Center assisted the Russian State ian composers at the Russian imperial court. Also in the planning Museum in publishing the proceedings of the museum’s April  stage is a collaborative project with the Hermitage on saving out- seminar “The Problems of Storage and Restoration of Art door sculpture. Museum Collections.” The publication features over  papers on A major new resource at the Center will be the Nicolaas a range of conservation and preventive conservation topics. Witsen Information Facility. In  the government of the Center staff is working closely with Vladimir A. Yakovlev, Netherlands, through the Ministry of Education, Culture, and governor of St. Petersburg, and other city authorities to ensure Science and the Ministry of Foreign Affairs, decided to establish that the  celebration attracts international attention to St. the Witsen Information Facility at the Center in honor of the th- Petersburg’s conservation needs. Support for the Center and its century Dutch scholar and mayor of Amsterdam who fostered early mission has also come from the national government. Mikhail Dutch-Russian relations. This generous contribution has funded Shvydkoy—who was appointed minister of culture of the Russian several new initiatives in information services to assist the Center’s Federation this spring—joined the Center’s board of directors in client institutions. These include: () the first and exclusive office in September  and has issued a protocol of understanding from Russia of the Art Loss Register; () a specialized preservation the Russian Ministry of Culture that strengthens the Center’s library of foreign and Russian reference sources; () an electronic work in the region. communications system linking the Center and its constituent orga- Also joining the Center’s board of directors is Mikhail Pio- nizations to other international databases and libraries; and () a trovski, director of the State Hermitage Museum. In a press release desktop publishing unit. issued jointly by the Center and the Hermitage in September , The Witsen Information Facility is scheduled to open at the he announced that the Center “has come through its initial phase Center before the end of . The Center will also launch its Web of development by showing that it can organize exactly the types of site (www.artsave.ru). The Web site and information facility will collaboration in conservation that are most needed here. . . . Now not only allow the work of the Center to be followed around the we will take a leading role in the St. Petersburg International Center world but will also provide its Russian users with the kind of inter- to support our city’s conservation needs.” national access to information and colleagues that can enhance their Thanks to the generosity of the St. Petersburg municipal own conservation efforts. government, the Center has been able to take possession of the historic Trubetskoy-Naryshkin Mansion with the understanding

Grants, Research, and Advocacy that the Center will restore and maintain this property. In keeping with its mission, the Center sees the renovation of its own home as One of the Center’s objectives is to offer Russian professionals a model for the restoration of other historic properties throughout increased opportunities for professional exchange and study. In that the city and is in the process of developing a fund-raising campaign context, the Center has provided Russian conservators, curators, to meet this goal. and conservation scientists with the opportunity to travel to the Aleksey Gibson is a research assistant with the GCI. Jane Siena Talley West. During –, under the Center’s auspices, the Royal is a GCI senior project specialist and president of the St. Petersburg Library in The Hague, the Centre des recherches sur la conserva- International Center for Preservation. tion des documents graphiques in Paris, and the  hosted profes- sionals from St. Petersburg who engaged in research and study. In the summer and fall of , the Center also gave travel grants to

22 Conservation, The GCI Newsletter lVolume 15, Number 3 2000 lNews in Conservation NewProjects Environmental Guidelines Acknowledging this need, the American Society for Heating, Refrigerat- for Collections ing, and Air-Conditioning Engineers () began a process in the late s to add a chapter on air-conditioning sys- tems in museums, libraries, and archives to their ASHRAE Handbook. This appeared as chapter  in the  edition. Chapters in  handbooks are the efforts of committees of recognized experts and are frequently revised. It is not uncommon for a new chapter to require several revisions at three-year intervals. Until recently, mechanical engineers did The —in collaboration with the not possess their own professional techni- Canadian Conservation Institute, conser- cal resources to guide them in designing vators, and several architects and engineers air-conditioning systems for museums, in private practice and academia—have libraries, and archives when such systems begun the second revision. Changes will were specified. Some of the information reflect a better balance of gaseous and that engineers needed concerning environ- particulate filtration with temperature and mental specifications was available but relative humidity needs of collections. dispersed in many locations within the There will also be a slightly altered overall conservation literature. continued on page 

Performance of Pollutant Adsorbents

Air quality in museums is a major concern In the late s, the  conducted because of the role that pollutants can play research evaluating common adsorbents in the deterioration of works of art used in conservation, including activated indoors—and within indoor microenviron- carbon, potassium permanganate, and silica ments such as display cases and storage gel. This research did not point to an opti- cabinets. Microclimates with inferior air mum adsorbent material. Each material had quality (due to infiltration of outdoor- drawbacks and advantages. Since that time, generated pollutants or indoor-generated new adsorbents have been developed and pollutants) are often treated by installing an marketed, including zeolites, zinc oxide, adsorbent material inside the display case calcium oxides, calcium carbonates, and or storage cabinet. continued on page  GCI News Conservation, The GCI Newsletter lVolume 15, Number 3 2000 lGCI News 23 Project Updates Environmental Guidelines continued from page  Conservation Completed organization to the chapter. This reference material will apply equally to new con- on St. Vitus Mosaic struction projects and to historic building retrofits. Feedback on the current content of chapter  is eagerly sought from con- servators and engineers alike. For further information, please contact either James Druzik or Cecily Grzywacz at the . The project is expected to last for at least the next two years.

Pollutant Adsorbents continued from page  An eight-year international collaboration Divided by Gothic spires into three adsorbents impregnated with acid neutral- among scientists, art historians, and conser- sections, The Last Judgment depicts Christ izing hydroxides. (Research at the Univer- vators culminated in Prague on September surrounded by angels in the central panel, sity of Glasgow is looking at catalytic , , with the unveiling of The Last and scenes of heaven and of hell in the two materials to remove hydrogen sulfide.) Judgment, a th-century glass mosaic that side panels. The brilliantly colored mosaic The fundamental questions regard- is one of the Czech Republic’s most signifi- comprises more than a million small glass ing adsorbents—such as which material cant cultural treasures. Czech President tiles and stone pebbles, in more than  should be used for which gaseous pollu- Vaclav Havel joined senior Getty staff at St. different hues. Until now, conservators tants, how much sorbent per enclosure Vitus Cathedral for the first public presen- have been unable to prevent the recurrence volume is necessary, and what is the length tation of the mosaic following completion of a grayish layer of corrosion that of time that each adsorbent is effective— of the conservation work that was under- obscures the mosaic. have not been systemically addressed. taken by the  and the Office of the Presi- The current conservation effort Recognizing the importance of answering dent of the Czech Republic. required extensive scientific and art-histor- these questions, the  has developed a The Last Judgment, the earliest and ical research and the development of new research project to evaluate the perfor- most important monumental exterior conservation methods and materials. In the mance of pollutant adsorbents. medieval mosaic north of the Alps, covers process, vital international exchange was This new project will test commer-  square meters ( square feet) of the facilitated. The challenge was not merely to cially available adsorbents to determine cathedral’s south facade. Since its creation clean the fragile mosaic but to ensure its their capacity for individual pollutants and in , the glass mosaic has rarely been future survival by coming up with a coating their effectiveness in removing the gas seen in its full splendor. It has faced that would stabilize and protect it, prevent- from a microenvironment. Studies will repeated threats from wars to fires—and, ing further deterioration and allowing it to include monitoring spent adsorbents for more recently, environmental pollutants. remain visible. release of the gases (i.e., if the adsorbent has adsorbed all of the pollutant that it can, Eliska Fucíková, director of the National Heritage Department in will it gradually release the potentially the Office of the Czech President, damaging gas back into the environment?). and Timothy P. Whalen, director of the GCI, listen to Czech President The project, now in the design phase, Vaclav Havel at the ceremony will begin testing in early . For further marking the completion of conser- vation of The Last Judgment mosaic. information, please contact James Druzik Photo: Francesca Piqué. or Cecily Grzywacz at the .

24 Conservation, The GCI Newsletter lVolume 15, Number 3 2000 lGCI News América Tropical

The  and its three project partners— El Pueblo de Los Angeles, the El Pueblo The Last Judgment mosaic on St. Vitus Cathedral, following conservation. Photo: Dusan Stulik. Commission, and the El Pueblo Parks Association—are cooperating to complete work on the conservation and presentation of the David Alfaro Siqueiros mural The project team began by analyzing own holdings of related material now América Tropical, in El Pueblo de Los , the mosaic’s material and decay products to exceed items. Conservators who had Angeles Historic Monument. understand the process of deterioration. worked on earlier restorations of the Painted in  on the side of the   Over the course of several years, they then mosaic, in the s and s, were also Italian Hall, the controversial mural, which tested numerous approaches to cleaning brought into the process, giving the project depicts a Mexican Indian crucified in a and protecting the mosaic. Actual treat- not only a multinational but also a multi- Mesoamerican landscape, was covered over ment of the mosaic got under way two and generational character. with white paint after its creation. Though a half years ago. The central panel was The results of the project team’s América Tropical deteriorated in the , fi completed in the summer of the right ndings will be shared as a service to the decades that followed, it remains the most , fi fi panel in the summer of and the nal, eld through publications and a sympo- important outdoor mural in Los Angeles. .  left panel in the summer of A team of sium in June . Additionally, the team The project’s goal is to make the painting  and Czech conservators cleaned the has developed a mosaic maintenance accessible to the public and to provide mosaic using special microsandblasters, and protocol, to be carried out under the visitors with an understanding of its his- they painstakingly applied a multilayer pro- supervision of Prague Castle to help ensure toric context. tective polymer coating adapted from the the long-term preservation of the conser- The project partners are working aerospace and medical industries. This is vation work. together on several fronts. First is the fi the rst time that the high-tech coating— In recognition of his substantial con- design of a shelter and a viewing platform developed in collaboration with the tribution to the mosaic’s conservation, for the mural. The architectural firm of Department of Materials Science Engi- Dusan Stulik, the mosaic’s project manager Pugh+Scarpa is designing a shelter for the  neering at the University of California, Los for the , was awarded the Presidential mural that will meet three criteria—to pro-  Angeles—has been applied for art conser- Medal of the Czech Republic. (Stulik, a tect the mural as much as possible from the vation purposes. senior scientist, is himself a native of elements, to blend in with the surrounding The project also contributed to major Prague.) In addition, the J. Paul Getty historic district, and to allow the entire advances in the art historical analysis of Trust and the Getty Conservation Institute mural to be seen from a viewing platform. The Last Judgment mosaic. Archival hold- were each awarded the Presidential Medal. The final conservation and cleaning ings related to the mosaic have expanded of the mural will occur once the new shel- with the discovery of a number of historical ter is in place. América Tropical is stable in documents and photographs, as well as its present condition, and it will be padded  extensive new documentation. The ’s and boxed during the rooftop construction

Conservation, The GCI Newsletter lVolume 15, Number 3 2000 lGCI News 25 phase of the project. Following construc- Documentation of tion, the conservation and cleaning will take approximately three months. Hieroglyph Stairway Another part of the project is an in Copán interpretative center for the mural. América Tropical is an important monument of both Los Angeles history and the Mexican mural movement. The design firm of  Magic has begun work on the didactic materials and on the design of the interpre- tive center, to be housed in the historic Sepulveda House. Access to the rooftop viewing platform will be through the inter- pretive center. As a part of the ’s Maya Initiative— imum. Because the site is protected by a Completion of the project will which focuses on advancing regional con- large tarpaulin suspended only a few feet require fund-raising. In addition to the servation practice and collaboration among from the surface, hundreds of camera funding that the , the City of Los the countries of the area—the  is setups were required to obtain the , Angeles, the Friends of Heritage involved in a partnership with the Instituto photographs and over , control obser- Preservation, and other foundations have Hondureño de Antropología e Historia vations necessary to complete the project. committed to the project, an additional () to develop a conservation plan for The photography is already being used as a  million is needed to complete work. the hieroglyphic stairway at the Maya site basis for the condition assessment. The data A fund-raising campaign began in late of Copán in Honduras. The stairway,  collected provide a unique record of the  to raise this sum. meters wide by  meters high ( feet by stairway and have the potential—by means The current timetable to which the  feet), is composed of  steps with over of a digital photogrammetry workstation— project partners are committed calls for , intricately carved Maya glyphs. It to produce a three-dimensional model of work to be completed by the spring of was rediscovered a century ago after being the stairway to millimeter precision. , in time for this significant monument buried for over a thousand years. of history and art to be made accessible to The  commissioned a measured the public  years after its creation. survey to gather the precise data required to provide a condition evaluation, create

A detail of the Siqueiros mural a basis for site monitoring, and guide an A detail of the hieroglyphic stairway América Tropical. Photo: Nancy Kaye. intervention strategy. Digital photogram- at Copán. Photo: William S. Ginell. metry was the survey method selected because of its capability of providing a precise map of the surface features. The site survey, which was conducted in June , consists of two elements: overlap- ping stereo photography, done with a specialized survey (metric) camera, and survey observations recorded with a total station. Photarc Surveys of the United Kingdom was selected to carry out the photography, and the  staff gathered the survey measurements. Measures were taken to protect both the stairway and the survey team and to ensure that contact with the stairway’s stone surfaces was kept to an absolute min-

26 Conservation, The GCI Newsletter lVolume 15, Number 3 2000 lGCI News Recent Events Tributes Meeting on Photographic A Tribute to Alessandra Preservation Melucco Vaccaro

A three-day meeting on photographic Thirty conservators, curators, and Conservator, teacher, and writer Alessan- preservation was held in early August at conservation scientists participated in the dra Melucco Vaccaro passed away in Rome the Image Permanence Institute () in discussions in Rochester. Included were in September  after a long illness. Rochester, New York, cosponsored by the conservation scientists from the , the Alessandra was an esteemed and val-  and the . The purpose of the meeting , and the Research Center for the Con- ued colleague of the staff of the , who was to identify and prioritize important servation of Graphic Documents in Paris. contributed in various ways to the work of conservation and research issues with Also attending were curators from the Institute. As one of the editors of the regard to the preservation of photographic Eastman House; conservators and educa- ’s  publication Historical and Philo- collections. In addition, those attending tors from Delaware, New York, and sophical Issues in the Conservation of Cul- discussed the feasibility and impact of Denmark, and from the J. Paul Getty tural Heritage, her very valuable knowledge various photographic conservation Museum; Mellon advanced fellows in pho- of modern conservation theory and archae- research activities and attempted to iden- tographic conservation; and conservators ological conservation helped to shape the tify potential collaborations and directions in private practice. form and substance of the book. She was for future research. The meeting was a unique opportu- an engaged and thoughtful participant in nity for a broad and open discussion of the the  Conference on Conservation of current state of research in photographic Archaeological Sites in the Mediterranean collections. Conservators, curators, and Region, organized by the  and the Getty conservation scientists had the chance to Museum. She also participated in the ini- exchange ideas on research approaches, tial  California meeting that launched priorities, and partnerships. Little has been the Institute’s research on the values of done until now related to the characteriza- heritage conservation. tion of photo materials, their deterioration, Born in , Alessandra studied and their reaction to treatments; it is hoped classical archaeology at the University of that this meeting, and subsequent discus- Rome, under the direction of Ranuccio sions, will result in valuable new research Bianchi Bandinelli. After her graduation, that will advance the state of photographic she joined the Ministry of Cultural Her- conservation. itage and worked at the Soprintendenza alle Antichità in Florence and in Ostia Antica. From there, she moved on to a position as curator at the Museo dell’Alto Medioevo in Rome. As the director of the Department of Archaeological Conservation at the Istituto Centrale per il Restauro in Rome from  to , she oversaw numerous con-

Conservation, The GCI Newsletter lVolume 15, Number 3 2000 lGCI News 27 A Tribute to Leonetto Tintori

servation projects, including the work done Leonetto Tintori, sculptor, painter, and treating paintings. In the aftermath of the on the Riace bronzes, the equestrian monu- internationally eminent wall paintings  flood in Florence, the group success- ment of Marcus Aurelius of the Capi- conservator, died in July  at his home fully introduced new measures for the tolium, the Arch of Constantine, and in Vainella, near Prato, Italy. He was  emergency stabilization and consolidation Trajan’s Column. years old. of wall paintings and paintings on wood. She went on to teach architectural Leonetto was part of a generation of In each conservation project, and archaeological conservation at the men and women whose lives and careers Leonetto saw the need to understand the University of Venice and at the Istituto are inextricably linked to the development original painting technique—not only to Suor Orsola Benincasa in Naples. During of what is now called conservation science. further his knowledge and appreciation of her last five years, she directed a section of The son of a farmer, he entered the the artistic achievement but as a require- the Central Office of Cultural and Envi- restoration field as an imbianchino, or wall ment for the proper identification of the ronmental Heritage of the Ministry of repairer and painter. He had trained as an conservation methods and materials com- Cultural and Environmental Affairs that artist in his hometown of Prato, but his patible with those used by the artist. When dealt with the protection of cultural land- knowledge of restoration and conservation he could not find adequate answers for scapes and with relationships among inter- was earned on the job. Under the guidance complex conservation problems, he sought national organizations. Through this work, of a well-known Florentine painter, expertise from other professions, and he she was very active in organizations such as Ardengo Soffici, whose house he was deco- was one of the first conservators to collabo- , the World Heritage Center, and rating, Leonetto started working as a con- rate with scientists. He was also a pioneer the Council of Europe. servator, repairing some th-century wall in insisting upon documentation, establish- Greatly concerned with the conser- paintings discovered under the whitewash. ing a tradition of detailed reports with sys- vation of archaeological sites, she was one He went on to work on the most tematic use of photographs. Leonetto was of the promoters and directors of the Carta important cycles of wall paintings in Italy. among the first in the field to publish del Rischio project (the risk map of cul- By the mid-s, Leonetto was part of reports on his work, collaborating on these tural heritage) and the EuroMed project, Ugo Procacci’s restoration group in Flo- articles with other professionals. Conserva- Programmation Integrée des Sites rence, working on wall paintings by Giotto, tors, scientists, and art historians from Archéologiques (). During her career, Simone Martini, Masaccio, Piero della abroad came to study and exchange ideas she authored a large number of articles and Francesca, and many others. At the end of with him. monographs on issues of archaeological World War , he achieved renown for his The quality of his conservation work conservation and the protection and man- part in saving the wall paintings in the is only a part of his legacy, for Leonetto agement of cultural landscapes. For these Cimitero Monumentale in Pisa. By the was also a natural teacher, a great colleague, and her many other contributions to the s he had his own conservation team, a tireless student, and a genuine innovator. field, Alessandra will long be remembered. which for  years studied original tech- In his later years, Leonetto and his wife niques and materials, collaborated with sci- Elena turned their house into an interna- entists, and introduced new materials for tional school and laboratory for the study of the ancient art of painting a fresco.

28 Conservation, The GCI Newsletter lVolume 15, Number 3 2000 lGCI News Publications Cave Temples of Mogao  were found sealed in one of the caves and then dispersed throughout the world. Art and History on the Silk Road Illustrated in color throughout, Cave Temples of Mogao combines lavish pho- By Roderick Whitfield, Susan Whitfield, tographs of the caves and their art with the and Neville Agnew fascinating history of Mogao, Dunhuang, and the Silk Road to create a vivid portrait of this remarkable site. Chapters discuss the development of the cave temples, the iconography of the wall paintings, and the

Leonetto Tintori. Photo: Francesca Piqué. extraordinary story of the rare manu- scripts—including the oldest dated printed book in existence, a th-century copy of A visit to the house was a journey to a place the Diamond Sutra. Also discussed are the wholly devoted to art, art making, and an collaboration between the Getty Conserva- understanding of traditional techniques tion Institute and Chinese authorities in and materials. A stroll in the garden conservation projects at Mogao and the brought encounters with sculptures large ways in which the site can be visited today. and small that waited like old friends along The publication of this book coincides the path. The walls of the house and stu- with the centenary of the discovery of the dios were used as panels where students manuscripts in the Library Cave. practiced all aspects and variations of Roderick Whitfield is Percival David wall painting techniques, from mixing Professor of Chinese and East Asian Art, and laying on the lime plaster to applying School of Oriental and African Studies, the paint made with mineral pigments University of London, and corresponding dispersed in water. fellow of the Dunhuang Academy. Susan In this small corner of paradise, Whitfield is head of the International Dun- Leonetto—after a busy career as a wall huang Project, British Library. Neville paintings conservator—continued to study, Agnew, who has worked on conservation The Mogao grottoes in China, situated experiment, write, and make his own art projects at Mogao for  years, is principal near the oasis town of Dunhuang on the until his death. project specialist at the Getty Conservation fabled Silk Road, constitute one of the Leonetto Tintori’s main desire was to Institute, a research fellow of the Dun- world’s most significant sites of Buddhist truly understand how great artists created huang Academy, and the editor of Conser- art. In some five hundred caves carved into their works. He believed that it was only vation of Ancient Sites on the Silk Road.. ff through scientific analysis and testing that rock cli s at the edge of the Gobi Desert , this could be achieved. His efforts have are preserved years of exquisite Conservation and Cultural Heritage series influenced countless conservators and murals and sculpture. Mogao, founded by 144 pages, 8 x 10 inches 144 color and 12 b/w illustrations, 1 map artists. His experience and intellect—and Buddhist monks as an isolated monastery ISBN 0-89236-585-4, paper, $29.95 his passion for learning and experiment- in the late fourth century, evolved into an ing—will be sorely missed. artistic and spiritual mecca whose renown extended from the Chinese capital to the far western kingdoms of the Silk Road. Among its treasures are miles of stunning wall paintings, more than , statues, magnificent works on silk and paper, and thousands of ancient manuscripts, such as sutras, poems, and prayer sheets, which in

Conservation, The GCI Newsletter lVolume 15, Number 3 2000 lGCI News 29 Staff Profiles Seismic Stabilization of Valerie Greathouse Historic Adobe Structures Reference Librarian, Final Report of the Information & Communications Getty Seismic Adobe Project

By E. Leroy Tolles, Edna E. Kimbro, Frederick A. Webster, and William S. Ginell Dennis Keeley

This book describes tests performed on model adobe buildings to evaluate seismic damage mitigation techniques applicable to the retrofitting of historic and culturally significant adobe structures. Part of the ’s Getty Seismic Adobe Project (), the three-year program outlined in this volume was designed to develop and test minimally invasive, inexpensive, and easily implemented methods of protecting such structures from severe earthquake damage. Small- and large-scale models were tested on computer-controlled shaking tables at Kevin Ellis Stanford University and at the  Earth- quake Engineering Laboratory in the Senior Technical Support Specialist, Administration Republic of Macedonia, respectively. The authors identify typical failure modes of scientist at the Getty Conservation adobe structures and describe specific Institute and was project director of . retrofit techniques to help minimize such Tolles, Webster, and Kimbro are coauthors, failures. Extensive photographic documen- Dennis Keeley with Anthony Crosby, of Survey of tation is included. Damage to Historic Adobe Buildings after the E. Leroy Tolles is a structural engi- January  Northridge Earthquake. neer with  & Associates and was princi-  pal investigator for . Edna E. Kimbro GCI Scientific Program Reports series

1 is an architectural conservator and histo- 158 pages, 8 ⁄2 x 11 inches rian specializing in the preservation of His- 286 b/w illustrations, 15 drawings panic-era buildings and material culture. ISBN 0-89236-587-0, paper, $40.00 Frederick A. Webster is a civil engineer who specializes in design, repair, and retrofitting of historic buildings. William S. Ginell is a senior conservation research

30 Conservation, The GCI Newsletter lVolume 15, Number 3 2000 lGCI News Valerie Greathouse is on the after reading a children’s nies, and her career as an infor- AATA/Bibliographic Conser- staff of the ’s Information magazine article about mation professional included vation Information Network Center, where she primarily Tutankhamun and the daugh- research and training in infor- database. She then joined the does reference and research ter of Akhenaten. mation retrieval, consulting in staff of the Information Center. work, recommending informa- After earning a B.A. in information management sys- Her outside interests tion strategies in conservation psychology from  (with a tems and database design, and include not only history and to Getty staff and conservators minor in anthropology and marketing of information sys- archaeology but also the per- worldwide. She also serves as archaeology), she took a tems and services. forming arts, photography, liaison to the Getty Research research position in mental In  she got a call cruising the California Channel Library and represents the  health evaluation at  and from a former colleague who Islands in her family’s sailboat on committees for the Library’s entered the School of Public was doing temporary work for (visiting the Chumash rock art online catalogue. Health’s master’s program. the ’s Art and Archaeology site on Santa Cruz Island), and Valerie grew up in Her master’s research in behav- Technical Abstracts (AATA). beachcombing and kayaking in Los Angeles. Her father was a ioral sciences and education The friend told her, “This is Mexico’s Sea of Cortez. In sound effects artist and engi- involved the retrieval, analysis, your kind of place—indexing addition to her position at the neer at  Radio. Her and dissemination of evalua- and abstracting, online data- , Valerie has, as she puts it, mother—who worked in tion information. During this bases, and Nefertari.” After worked as a mom for  years aerospace and raised money period, she managed a large two months in a temporary and been married forever. for medical research—had research grant at  and position, Valerie became assis- intended to be a librarian, and supervised an abstracting and tant editor of AATA, where she Valerie became a bibliophile at indexing unit. In the following remained for five years. She an early age, one with a passion years, she worked for several also worked on the Conserva- for archaeology that developed information services compa- tion Thesaurus and the

As part of the ’s administra- After high school— becoming a systems program- racer since , he is a board tive group, Kevin Ellis manages where he excelled in water mer. While there, he worked on member of the Alamitos Bay the Institute’s computer polo—Kevin did construction the development of informa- Yacht Club, as well as one hardware and helps coordinate work for a couple of years tion systems for hospitals. of the club’s principal race implementation of Getty before being hired by City In  he was hired by officers. Perhaps his most Trust data acquisition systems. National Bank as an entry-level the  to provide on-site com- memorable yachting experi- He also works closely with the data processor. At the same puter support at the Institute’s ence was as part of a five-man Institute’s liaison to Informa- time, he started taking courses original headquarters in the crew on a -day, ,-mile tion Technology Services at in computer science and busi- Marina del Rey section of Los trip aboard a racing sloop that the Getty. ness administration at Glendale Angeles. He went on to imple- sailed from Honolulu to Long Born in Los Angeles, College. After a year with the ment the Institute’s first inter- Beach in the summer of . Kevin was raised in the suburb bank, he got a job with the Jet nal network and project of Glendale. His parents were Propulsion Laboratory in administration system. Since also native Angelenos. His Pasadena, where he worked ini- the ’s move to the Getty father was a computer consul- tially doing computer service Center in , his daily role tant, and Kevin, at the age of and repair, then later helped has changed—he now has more , regularly accompanied him install and maintain ’s first administrative and budgetary at night to large computer facil- local area network. Although he responsibilities. ities where he had rented time enjoyed the exciting and ener- Kevin—who began boat- for information processing. getic environment at , he left ing with his family at the age of These were Kevin’s first mem- after five years to join a start-up two—can be found on week- ories of computers. software company where he ends sailing the waters off Long could pursue his interest in Beach. A competitive yacht

Conservation, The GCI Newsletter lVolume 15, Number 3 2000 lGCI News 31 Feature 5 Surface Cleaning and Conservation

Dialogue 10 Finding a Certain Balance A Discussion about Surface Cleaning

News in 16 The Gels Cleaning Research Conservation Project

20 Preservation in St. Petersburg

GCI News 23 Projects, Events, Publications, and Staff