The Getty Conservation Institute recently began a collaborative research project on the conservation of photographic materials. The GCI's partners in this initial phase of the project include the Image Permanence Institute (IPI) of the Rochester Institute of Technology and the Centre de recherches sur la conservation des documents graphiques (CRCDG), an independent entity of the Centre national de la recherche scientifique of the French Ministry of Culture.
The ultimate aim of the project is to provide a foundation for the later development of new tools to diagnose the causes of deterioration of photographic materials, and for the development of new treatment and preventive conservation strategies for these materials.
This international collaboration grew out of a GCI feasibility study that included a review of relevant art conservation literature, a 1999 meeting at the IPI to discuss the state of photographic conservation, and consultations with conservators, curators, and scientists to identify the conservation research needs in the field of photography.
One of the primary reasons for this initiative is the change occurring in photography. As digital photography supplants classical (i.e., chemical) photography, there is a danger that crucial knowledge might be lost regarding past artistic, experimental, and commercial photographic processes—knowledge needed by photography conservators and art historians. Indeed, several major film manufacturers who were on the forefront of photochemical and photographic research recently discontinued their work in this area. Another reason for the project is the lack of comprehensive scientific research into conservation issues in photography, as compared with research devoted to other artistic mediums.
The project focuses on the characterization of photographic materials, with the objective of advancing methods to identify photographic processes and postprocessing treatment of photographs (as needed for the development of appropriate conservation and treatment strategies). As part of its work, the project will:
- prepare an in-depth review of the scientific and conservation literature related to the conservation of photographs;
- develop and test scientific methodologies for instrumental and analytical characterization of photographic materials;
- investigate and test new methods of photograph microsampling and nondestructive investigation of photographic material;
- develop a practical, instrument-based decision tree for identification of photographic processes, their variants, and postprocessing treatments;
- prepare an atlas of analytical signatures of different photographic processes that can aid conservators and museum specialists in the identification of photographic materials.
Each partner in the project will undertake selected aspects of the work. The project capitalizes on GCI expertise in characterization of art objects, identification of organic materials and binding media, X-ray fluorescence, electron microscopy, infrared analysis, gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry techniques, and other analytical methodologies. Utilizing its experience and facilities, the GCI hopes to advance characterization of photographic material beyond the optical microscopy techniques used by the field today. The use of an analytical approach as a part of the photographic material characterization strategy will allow identification of major photographic processes, process variants, and postprocessing treatments. The analytical approach will help identify important cases of complex and combination processes, which are, thus far, beyond the capabilities of optical microscopy techniques. This approach will provide conservators and museum specialists with the data needed to develop treatment and preventive conservation strategies.
The IPI's role in the project will focus on the development of an advanced—and analytical—instrumentation-based methodology for the identification of photographic materials. The research will use the IPI's study collection of photographic materials, and the research will be performed both at the IPI and the GCI laboratories.
The CRCDG will develop microsampling techniques for the study of multilayer structures of photographic prints and film plates, paper-based photographic substrates, and the chemistry of baryta and gelatin layers on 19th- and 20th-century photographic materials. The Center will also participate in the preparation of test samples needed for the development and testing of photographic material identification methodologies.
At the GCI, Dusan Stulik is the manager of the project, and Alberto de Tagle serves as the project advisor. The project core team also includes James Druzik and Herant Khanjian.
Analysis of Early Photographs
As part of the GCI's feasibility study for its new collaborative project on the conservation of photographic materials, GCI staff conducted an analysis of an album of early photographic prints attributed to French photographer Eugène Durieu, notable not only because of his collaborative work with painter Eugène Delacroix but also for his role as president of the Société française de photographie.
The Durieu Album, from the George Eastman House collection, contains 119 photographic prints dated between 1851 and 1855. The photographs, which are primarily salt prints or albuminized salt prints, are in various states of preservation. Some backs of the album pages show readable image transfer from the prints on the next page. However, image transfer—usually associated with catalytic effects of platinum—is not usually found with prints created during the same period as the Durieu photographs.
To answer questions regarding the presence of platinum in Durieu's prints—and to explore the use of noninvasive analytical techniques—a collaborative project was established between the GCI and the Eastman House. Alexandra Botelho—a Mellon Fellow in the photographic conservation program at Eastman who has been studying the album—worked with GCI scientists Dusan Stulik and Herant Khanjian on the analytical investigation.
The photographs were analyzed using techniques that did not require the removal of samples. X-ray fluorescence was used to study toning procedures and to search for a source of the image transfers. The analysis showed that a majority of the prints were toned with platinum and that some were toned with both platinum and gold.
The nondestructive organic analysis of the varnish layers found on some prints was based on both reflection and ATR Fourier transfer infrared spectrometry. Wax and natural resin coatings were identified on varnished prints.
The GCI's analytical investigation of the album demonstrated that Durieu experimented—more then was previously known—with different toning and varnishing procedures. The platinum toning and the combination of platinum and gold toning found in the prints represent very early examples of the use of these procedures in photography. The image transfers in the album can be successfully explained as a result of platinum toning.
The analytical techniques used in the study will be further refined as part of the GCI's collaborative project on the conservation of photographic materials.