By Jeffrey Levin and Dusan Stulik

For photography, this is a time of transition. In recent years, chemical photography, which characterized classical photographic image making from its embryonic days, has abruptly given way to digital photography. With astonishing speed, the dominance of film in photography has come to an end.

The work produced by that age, however, remains with us. Millions and millions of photographs from film exist in libraries, archives, museums, and private collections around the world, documenting over a century and a half of public and private life, as well as constituting an important record of places, people, and things that have long since vanished. Preserving this significant segment of the world's heritage that depicts our past requires a comprehensive understanding of both the materials and the processes that went into the making of these photographs.

During the chemical photography period, there were several processes that were widely used, some of which are fairly well researched by photography conservators. These include albumen photographic prints, commonly produced in the nineteenth century, and silver gelatin black-and-white printing, used pervasively in the twentieth century. But these are only two of approximately one hundred fifty photographic processes that were developed and utilized during the nineteenth and twentieth centuries as inventors and artists searched for ways to improve upon existing photographic technologies. Connecting a particular photograph with a particular process can present a real challenge—but one that must be addressed if a photograph is going to receive appropriate treatment. Identifying the specific material in a photograph and the process by which a photograph was created is a critical first step in a photograph's conservation.

Indeed, at a 2000 meeting the Getty Conservation Institute organized with the Image Permanence Institute (IPI) in Rochester, New York, the development of better methodologies for the detailed characterization of photographic material was singled out as one of the highest priorities in photographic conservation. The meeting, which included more than thirty experts from around the world, led to the 2001 initiation of the GCIs Research on the Conservation of Photographs project, in partnership with the IPI and the Centre de recherches sur la conservation des documents graphiques (CRCDG) in Paris, as well as with the Department of Chemistry at California State University, Northridge, and the Paper Conservation department of the J. Paul Getty Museum. In the years since then, the project has researched and refined techniques that can help to identify more than fifty photographic processes. In addition, the project has grown to include other related initiatives that seek to improve the practice of photography conservation.

Identification of Materials

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Visual and microscopic observation are important starting points in the examination of photographs, but they cannot identify all photographic processes. Photographs can include inorganic and organic materials, often composed in complicated layered structures that sometimes can be more complicated than those of paintings. For example, among the most complicated photographic prints is a Polaroid, which is composed of up to nineteen layers of inorganic and organic materials—complex layers, many with a submicron thickness.

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A major part of the research project has been the development of scientific methods for the characterization of photographs and photographic material, using nondestructive analytical tools that the Institute has employed in other work—including X-ray fluorescence spectrometry (XRF) for the identification of inorganic materials and Fourier-transform infrared (FTIR) spectrometry for identifying organic materials. These tools provide us with analytical signatures that are associated with different photographic processes. The GCI is collecting these markers into an atlas of analytical signatures that, when complete, can assist curators and scientists in identifying the photographic processes that produced the images in their care—information that will be an important resource for photograph conservators and an aid to conservation.

The project has also developed a portable laboratory capable of conducting XRF, FTIR, and digital microscopy, and this has enabled the GCI to work with several different institutions with diverse photographic collections. No single collection includes images with all of the one hundred and fifty different processes represented, so the portable laboratory—which can be assembled in approximately forty minutes and can fit on a three-by-six-foot table—provides the opportunity to take the analytical tools to the collections rather than bringing photographic works from elsewhere to the GCI laboratories. This work has been conducted at the National Media Museum in Bradford, UK; the Société Française de Photographie in Paris; the George Eastman House in Rochester, New York; the Harry Ransom Center at the University of Texas in Austin; the Moravian Gallery in Brno, Czech Republic; and the Dresden Krone Archive at the Institüt für Angewandte Photophysik of Technische Universität Dresden in Germany.

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One important aspect of the GCI's research on materials is investigation into the baryta-layer coating, which began to be incorporated into black-and-white photographic paper by the end of the nineteenth century. There are two main reasons the coating was used: first, it sealed the paper, which might contain some impurities that can destroy photographic emulsion, and second, it produced a more brilliant image. In its research, the GCI has discovered that different photographic papers have different quantities of barium in the baryta layer. For example, modern photographic papers have a different amount of barium than those used in the beginning of the twentieth century, and an amount much different than that applied in the nineteenth century. This finding has great benefit for curators, because analysis of the baryta layer can help identify the age of a photographic print. It could, for instance, demonstrate that a print has been mistakenly—or fraudulently—identified as being much older than it actually is. GCI research has also found strontium in the baryta layer. This discovery is significant because the difference between the barium and strontium concentrations in papers varies greatly, and determining the ratio between those two elements in a particular paper can help to identify it.

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In January 2006, the GCI and Boston-based independent conservator Paul Messier presented a daylong symposium at the Getty Center on the scientific investigation of the baryta layer coating and its role in the identification, authentication, and provenance of twentieth-century silver gelatin photographs. More than eighty conservation scientists, photography conservators, photography historians, museum curators, photographers, and auction house representatives from North America and Europe attended. At the symposium, GCI staff and Messier made presentations on their independently conducted scientific investigations, which have identified a number of chemical and physical markers of baryta-coated black-and-white photographic paper (see Conservation, vol. 21, no. 1).

GCI research involving some specific photographs has yielded information that contributes to knowledge of the history of photography. For example, GCI scientific analysis of a gold-toned portrait of Abraham Lincoln, held in a private collection, resulted in a fuller understanding of the little-known auratype photographic process. In another instance, infrared and XRF analysis of a William Henry Fox Talbot experimental photograph dated 1854 at the National Media Museum in the United Kingdom indicated the use of collodion on the paper as well as the application of a baryta layer; if future research confirms that the print was indeed made by Talbot in 1854, this information would push back the date for the first known use of both of these processes.

Initiative in Central, Eastern, and Southern Europe

A major new component of the GCI's photography conservation project is an initiative to improve the conservation of photography collections in central, eastern, and southern Europe. Photograph conservation as a field of practice and study is relatively well developed in western Europe, but it is either in its infancy or nonexistent in these other regions of Europe. There are no university-level or other academic programs to prepare conservators for working with photographs and photograph collections. The needs of photograph collections in museums, archives, and private collections are only partially covered by paper conservators and other heritage preservation specialists—or not covered at all.

In 2006 the GCI conducted a feasibility study, surveying countries located in central, eastern, and southern Europe with a goal of determining how best to improve photograph conservation practice and education in the region. This study found significant interest among various cultural heritage organizations in the area to establish photograph conservation programs and practice. As a result, the GCI formed a partnership with two organizations in the Slovak Republic—the Academy of Fine Art and Design in Bratislava and the Slovak National Library in Martin—to develop a program of photograph conservation for the region.

The first program of this partnership was a four-day international symposium held in November 2007 in Bratislava, focused on developing preservation and conservation strategies for photograph collections located in central, eastern, and southern Europe, as well as encouraging photography research in the region. The goal of this symposium was to serve as a catalyst for an international collaboration to establish photograph education and training programs to preserve the region's photograph heritage.

The symposium was also an important first step in the development of the Institutes educational initiative for the region, scheduled to begin in summer 2008. The initiative involves a series of summer schools focusing on the theory and practice of photograph conservation, the organization and logistics of photograph conservation practice, and the development of photograph and photograph conservation research. The summer school program is being developed for conservators, art conservation educators, and cultural heritage specialists who are responsible for the care and preservation of photographs. Participants—who will ideally be midcareer conservators or cultural heritage specialists—will be chosen on the basis of their professional experience, the size of their photograph collections, and the likelihood that they will be able to disseminate the information through their own teaching and professional activities. Each multiweek summer school will be followed by a ten-month program of coordinated and mentored activities that participants will pursue within their own institutions, as well as through some targeted workshops and trips, as they apply the ideas and information presented during the summer sessions.

Photographic Materials Archive

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An important aspect of the GCI's photography research project is the creation of a reference collection of photographic material that will allow future generations of photograph conservators and scholars to research and authenticate photographs from the first century and a half of photography. Until now, no such archive has existed. Unfortunately for the field, the large photography companies—Kodak, Ilford, Fuji, Polaroid, and Agfa—did not save samples of the hundreds of different films and papers they developed for use in chemical photography. And although many museums have photographs collections, and some museums collect cameras and photographic equipment, there is no institution systematically collecting photographic materials.

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For that reason, the GCI decided to create an archive of photographic materials that will be part of the Institute's existing Reference Collection of art-related materials. As part of that effort, the Institute is reaching out to the public to provide material for the archive. Through the project's Web site and other venues, the GCI is seeking the public's help in saving photographic heritage by donating photographic materials, including samples of photographic paper and plates, film, and negatives, as well as sample books and dated photographs. The GCI is looking for examples of all types of materials dating back to the early nineteenth century, when photography began. The initial response to this appeal has been strong: people are sending materials from the United States and other areas of the world, including Europe and Africa. The growing archive of photographic materials is housed in the GCI's Reference Collection at the Getty Center in Los Angeles; it will be open to conservators, scientists, and researchers.

As chemical photography recedes in popular use, the critical moment to gather and disseminate information regarding this form of photography has arrived. Work must be undertaken now, before essential knowledge of the materials and processes that created these images is lost. It is hoped that the research efforts of the GCI, in partnership with other institutions, on the conservation of photographs will contribute to the preservation of this significant portion of our cultural heritage.

Jeffrey Levin is editor of Conservation, The GCI Newsletter. Dusan Stulik is a senior scientist with GCI Science; he heads the Institute's research on the conservation of photographs.