RAdICAL Workshop 2024

The 2024 Recent Advances in Characterizing Asian Lacquer (RAdICAL) workshop, held April 18–26, 2024, and co-organized with the Palace Museum, Beijing, was adapted to China’s specific work environment.

The five-day workshop included two pre-workshop days to offer training in microscopy for participants who had not previously received such training. It explored newly developed analytical procedures for acquiring detailed compositional information about Asian lacquers, their additives, and their European substitutes.

Conservators and scientists worked together in research teams to study and discuss historic lacquer samples. This was a unique opportunity for collaboration and discussion of topics such as the compositional variation in lacquered objects made in different geographical areas and time periods, the relevance of analytical research to the conservation and interpretation, and the identification of research priorities and potential collaborations.

The workshop aimed to:

• highlight the benefits that collaboration between scientists and conservators can provide
• enhance the understanding of a lacquered surface through the study of its stratigraphy and composition
• demonstrate new analytical protocols and the level of information that can be obtained using these methods
• provide participants with the tools necessary to use these methods, such as a marker compound database and custom data evaluation tools
• identify pressing analytical and conservation issues in the field and priorities for future research.

The workshop provided instruction in the following low-tech and high-tech procedures with the aim of identifying traditional and non-traditional materials in Asian lacquers:

• Visible and fluorescent light microscopic examination of chemically stained lacquer cross-sections which can provide visual, layer-specific information for a number of organic materials.
• Precision sample collection of discrete lacquer layers which permits layer-specific compositional information to be obtained.
• Pyrolysis-gas chromatography/ mass spectrometry with thermally assisted hydrolysis and methylation (THM-Py-GC/MS), which is a versatile method with excellent limits of detection.
• A systematic protocol for data analysis and interpretation using AMDIS (Automated Mass spectral Deconvolution and Identification System) and Excel, with a shared marker compound database that permits detection of a broad range of marker compounds even when present at trace levels.

The concepts taught in the workshop may also be applied to the study of materials other than lacquer.

Michael Schilling: Senior Scientist and head of organic materials research at the Getty Conservation Institute specializing in GC/MS and thermal analysis techniques

Arlen Heginbotham: Conservator of Decorative Arts and Sculpture at the J. Paul Getty Museum, specializing in the technical examination of furniture

Nanke Schellmann: Independent Conservator and Researcher at Schellmann Conservation in Munich, specializing in the conservation and analysis of mixed media objects and the characterization and treatment of degraded decorative surfaces.

Instructors were assisted by both English- and Chinese-speaking colleagues from the Getty Conservation Institute and the Palace Museum allowing for co-teaching sessions in English and Chinese.

Established in 1925, the Palace Museum is located in the imperial palace of the consecutive Ming (1368-1644) and Qing (1644-1911) dynasties. The magnificent architectural complex, also known as the Forbidden City, and the vast holdings of paintings, calligraphy, ceramics, and antiquities of the imperial collections make it one of the most prestigious museums in China and the world. In 1961, the State Council designated the former imperial residence as one of China's foremost-protected cultural heritage sites, and in 1987 it was listed as a UNESCO World Heritage site. The Conservation Department, consisting of conservation science laboratories and restoration studios, is responsible for the conservation and study of over 1.8 million cultural artifacts from the Palace Museum's collection.