In January 2006, the Getty Conservation Institute and Boston-based independent conservator Paul Messier presented a daylong symposium, "Understanding Twentieth-Century Photographs: The Baryta Layer," in conjunction with the Institute's Research on the Conservation of Photographs project. Held at the Getty Center, the symposium focused on the scientific investigation of the baryta-layer coating used in black-and-white photographic paper and its role in the identification, authentication, and provenance of twentieth-century silver gelatin photographs. In attendance were more than eighty participants, including conservation scientists, photography conservators, photography historians, museum curators, photographers, and auction house representatives from the United States, United Kingdom, France, Germany, Canada, and Mexico.

Scientific investigations conducted independently by the GCI and Messier have identified a number of chemical and physical markers of baryta-coated black-and-white photographic paper that can be used for provenance, authentication, and, in some cases, dating of photographic material and photographs.

Messier presented the results of his research in optical brighteners and discussed his extensive collection of well-documented photographic papers that became the focus of collaborative baryta-layer research with the GCI. Dusan Stulik, a GCI senior scientist, discussed this research, from the development and verification of the scientific methodology to its results and applications for both photography conservation and art-historical research. Future work will include application of the newly developed methodology to provenance and art-historical questions and to research in data mining and data interpretation of twentieth-century photographs.

GCI graduate intern Renaud Duverne presented research conducted on cross sections of photographs that has shown that detailed physical measurements, together with a study of the morphology and size of particles of the baryta layer, can also be used as markers to develop a provenance strategy for photographs. In addition, GCI research addressing important questions on the internal chemical stratigraphy of photographs was discussed by GCI Research Lab Associate Art Kaplan. David Miller, from the Department of Chemistry at California State University, Northridge, demonstrated that a study of both minor and trace chemical elements present in photographs is another potential tool for dealing with difficult provenance issues.

The second part of the symposium included a demonstration by GCI consultant Tram Vo of the new analytical methodology for determining the provenance of twentieth-century photography. The event concluded with a roundtable discussion of issues related to the authentication and provenance of photographs, current research in photographic conservation, and the need for a systematic worldwide development of a photographic materials reference collection.

For more information please visit the Getty Web site.