Eighteen conservators and scientists gathered at the Getty Center from 22-26 October 2012 to work together in research teams to prepare and test samples of historic lacquer from their own collections and present their analytical findings on the final day.
The five-day workshop provided instruction in two analytical procedures and a precision sampling technique and struck a balance between instruction, hands-on application to samples from museum collections, and directed group discussions.
The overall objectives of the workshop were:
• to demonstrate a particular analytical protocol and the level of information that can be gathered using these approaches and methods
• to provide participants with the tools necessary to make use of these approaches and methods, such as the Py-GC/MS marker compound database and an Excel evaluation form
• to highlight the benefits that collaboration between scientists and conservators can provide
• to identify pressing analytical and conservation issues and problems in the field, and priorities for future research
Areas of instruction during the workshop included:
• Precision sample collection of discrete layers within a lacquer sample.
• Visible and fluorescent light microscopic examination of chemically-stained lacquer cross-sections, which provides visual, layer-specific information for a number of organic materials when present in significant concentration.
• Pyrolysis-gas chromatography/mass spectrometry with thermally-assisted hydrolysis and methylation (THM-Py-GC/MS), a versatile method with excellent limits of detection.
• A systematic protocol for data analysis and interpretation based on GC/MS quantitative analysis software and a specialized Excel worksheet and marker compound database developed at the GCI, which permits detection of a broad range of compounds even when present at trace levels.
In the GCI's Characterization of Asian and European Lacquers project, development of a THM-Py-GC/MS procedure to study Asian and European lacquered objects led to surprising discoveries about the range of materials used by lacquer artists.
Michael Schilling: Senior Scientist and head of Organic Materials Research at the GCI, specializing in GC/MS and thermal analysis techniques.
Arlen Heginbotham: Associate Conservator of Decorative Arts and Sculpture at the J. Paul Getty Museum, specializing in the technical examination of furniture.
Nanke Schellmann: Furniture and Decorative Objects Conservator and Conservation Scientist, specializing in the characterization and treatment of degraded decorative surfaces.