By Dusan Stulik

The art of photography is near infancy when measured against the histories of other disciplines in the visual arts such as painting, sculpture, and decorative arts. For that reason, the conservation of photographic collections and photographic material—when compared to other museum conservation areas—is relatively young, lacking the level and sophistication of scientific and research support for the more established fields of art conservation.

Yet despite its relative youth, it is possible that classical photography—or, as we can call it, chemical photography—will not survive the 200th anniversary of the 1839 public announcement of Daguerre’s invention.

Since the 1980s, there have been significant advances in both digital technology and digital imaging. As in the 1960s, when the number of colored photographs produced worldwide first surpassed that of black and white, it is likely that the time is not distant when digital photography will be the primary technology used by photographers. With the increasing acceptance of digital photography, chemical photography might be relegated to a category of alternative photographic techniques and used primarily by enthusiasts of historical photographic processes and photographers wanting to explore those aesthetics that are unique to chemical photography.

If such predictions come true, there is a danger that these dramatic changes in photography will trigger a decrease in scientific research and knowledge related to chemical photography. In addition, the shift of major manufacturers of photographic material from chemical to digital photography or to some other industrial production (a move already under way) will jeopardize the preservation of manufacturing information and collections of materials related to chemical photography technology.

Identifying Research Needs

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It was with these issues in mind that the Getty Conservation Institute, in collaboration with other organizations, began exploring ways that it could help expand the existing body of knowledge regarding photographic conservation. The first major step in this process of identifying the essential needs in the field was a three-day meeting organized by the GCI and the Image Permanence Institute (IPI) in Rochester, New York, in August 2000. More than 30 conservators, conservation scientists, educators, and curators from around the world participated in the discussion, centering on the identification of the most important research issues related to the conservation of photographs and photographic materials.

At the meeting, a number of research ideas were suggested that encompassed many branches of photographic conservation and scientific research; there were also ideas focusing on ancillary issues, such as the presentation and exhibition of photographs, as well as art historical research. By the end of the meeting, one research issue emerged as dominant: the development of methodologies to enable more detailed characterization of photographic material. While other questions related to conservation treatment, handling, exhibition, storage, authentication, provenance, and the artistic techniques of individual photographers were held to be important, it was the consensus of the group that the first task should be a better understanding of the chemical structure and context of the photograph.

Subsequent to the meeting, the GCI Science group decided to test research ideas put forward in Rochester by conducting a small feasibility study in order to define the methods, structure, and goals of a possible full-scale research project more clearly. As part of that study, GCI scientists analyzed the Durieu Album (see Conservation, vol. 16, no. 2), one of the important objects in the photographic collection of the George Eastman House in Rochester. This private album of French photographer Eugène Durieu (1800–1874), renowned for his artistic collaboration with French painter Eugène Delacroix, contains 115 mounted photographs of landscapes, portraits, and nudes, as well as photographs of etchings by Rembrandt and Watteau.

In studying the Durieu Album, GCI scientists used nondestructive techniques—X-ray fluorescence (XRF) and Fourier transform infrared spectrometry (FTIR)—to analyze the photographs. XRF spectrometry, an important tool in conservation research and museum analytical practice, can identify and quantify the majority of chemical elements of the periodic table. Just as XRF analysis provides both qualitative and quantitative information about inorganic elements present in photographic material, FTIR provides information on organic components. Both techniques are nondestructive: neither sampling nor direct contact with the photograph is required.

XRF spectrometry and FTIR analysis of the Durieu photographs in the album indicated that Durieu experimented with different toning procedures on photographs throughout the album. For example, a number of photos were apparently toned with platinum; several were toned with gold; and several were not toned at all. Even more intriguing, some photos combined both platinum and gold toning.

These results were unexpected, because the earliest published reference to platinum toning was in 1856. A number of photographs in the album were printed in 1854, so it is possible that Durieu’s photographs are the oldest existing examples of platinum toning. Furthermore, the findings suggest that these photographs are the earliest known examples of combination toning. The FTIR results also provided interesting insights into early experimentation with organic coatings and varnishes.

The successful use of XRF spectrometry and FTIR analysis on the Durieu photographs demonstrated the potential for employing these nondestructive techniques for research on the characterization of photographic material and for the identification of photographic processes.

A Collaborative Project

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Following the completion of the feasibility study, a full collaborative research project focusing on the identification of photographic material was developed. The project on the conservation of photographic collections, officially begun in July 2001, is a collaboration among the GCI, the IPI, and the Centre de recherches sur la conservation des documents graphiques (CRCDG) in Paris. The project seeks to advance techniques for identifying important variations in photographic processes, providing greater insight into the processing chemistry and postprocessing chemical treatment of photographs. The first phase of the project is focused on the characterization of photographic material by use of instrumental analytical techniques.

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The project partners are working both independently and collaboratively on several areas of research. For the identification of photographic processes, the IPI and the GCI are expanding a “decision tree” that was first developed by James Reilly, director of the IPI. The decision tree, once expanded by the inclusion of analytical techniques, can help identify process variants.

The CRCDG is currently developing microsampling techniques for the study of multilayer structures of photographic prints and film plates, paper-based photographic substrates, and the chemistry of both baryta and gelatin layers on 19th- and 20th-century photographic material. The CRCDG is also collaborating with the GCI on the preparation of well-defined test samples needed for the development and testing of scientific methodology for the identification of photographic material.

At the GCI, the project team is concentrating on analytical research using XRF spectrometry and FTIR analysis. A major focus of the project is to develop a methodology of nondestructive FTIR analysis of photographic material using reflection, attenuated reflection (ATR), and angle-resolved ATR analysis, as well as molecular mapping of cross sections of photographic material.

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As with all GCI projects, an important component of the work is the dissemination of project results to the broader conservation community. The collaborative research team meets regularly to exchange ideas and results, some of which were shared at the interim meeting of the ICOM Photographic Material Group in Paris in September 2001. Results of the collaborative research project with the George Eastman House and the Mellon Graduate Fellowship Program on the photographic analysis of the Durieu Album will be presented at the ICOM-CC conference in Rio de Janeiro in September 2002. And GCI studies on the quantitative XRF analysis of photographic material and on the FTIR analysis of photographic coatings and varnishes will be presented at the Conservation Science 2002 conference in Edinburgh in May 2002.

Dusan Stulik is a GCI senior scientist and the Institute’s manager for the conservation of photographic collections project.