The reproduction of realistic samples of Chinese export lacquer for research

Abstract

Three late-eighteenth-century to early-nineteenth-century objects made from Asian lacquer were analyzed using histochemical staining of cross-sections and pyrolysis-gas chromatography-mass spectrometry, and found to include laccol, and perilla oil and cedar oil, in contrast to urushiol alone, commonly used as an analytical marker for Asian lacquer. Sample set based on urushi made from laccol, and varied amounts of perilla oil and cedar oil were created and light aged in a xenon arc weatherometer, further aged in different levels of relative humidity, while physical changes were monitored by means of pH, gloss measurements, and autofluorescence during aging. The pH was dependent on initial composition. The study gave new understanding of autofluorescence in lacquers, and made clear that samples for experiments must include urushi, laccol, and thitsi, which have physical and chemical differences. The hypothesis that urushi has superior aging characteristics to laccol is not consistent with the results. The experiments also demonstrated that other ingredients constituting major additives are equally important to the behavior of lacquer as it ages.

The lacquer crafting of Ba state: Insights from a Warring States lacquer scabbard excavated from Lijiaba site (Chongqing, southwest China)

“…In accordance to Py-GC/MS results, the two characteristic catechol markers 1,2-dimethoxy-pentadecylbenzene (C 23 H 40 O 2 , t r =22.57 min) and 1,2-dimethoxy-pentadecenylbenzene (C 23 H 38 O 2 , t r =22.45 min) were both detected in the tested sample confirming the Shengqi origin. Noteworthy, under THM pyrolysis conditions, kumanotanic acid, mazzeic acid and miyakoshic acid were detected at a low ratio and their presence could be correlated to an ageing process of the urushi sample in particular in presence of siccative oil as reported previously (Schilling et al 2016;Webb, Schilling, Chang 2016, Tamburini et al 2016. In comparison to direct Py-GC/MS analysis, the observed alkylbenzene series in the lacquer sample is reduced: only the n-hexylbenzene was present while n-heptylbenzene and n-octylbenzene were only detected at traces level.…”

Beyond the basics: A systematic approach for comprehensive analysis of organic materials in Asian lacquers

“…Exposure to light causes profound changes to its surface appearance and sensitivity to solvents (McSharry et al, 2011). To better understand this phenomenon, THM-Py-GC-MS was performed on residues extracted by droplets of water applied to the surfaces of Chinese and Japanese export lacquer replica panels that had been exposed to light in an Atlas weatherometer chamber (Webb et al, 2016). Surprisingly, the water extracts were composed almost entirely of isomers of mono-, di-, tri-, and tetra-carboxylated benzene (see Appendix 2), and the lacquer composition affected the final product distribution.…”

Was Lacquer the Key Ingredient for Luxurious Jinyin Pingtuo Products in the Tang Dynasty of China (AD 618–907)?

“…However, these microfractures, generally caused by light exposure, are very fine in the case of Asian lacquer (about 25 μm between two microcracks; Webb et al . ), whereas the ones present on the patches of the object under investigation were much bigger and unevenly distributed, ranging from 50 μm to 1 mm. The silver décor was cut into sheet, and designs were carved before being put in place on the object to be decorated (Zhang and Xu ; Liu and Wu ).…”

“…The presence of fine fractures on these patches and the slight luminescence shown under UV light suggested the possible use of Asian lacquer (Webb et al . ). However, these microfractures, generally caused by light exposure, are very fine in the case of Asian lacquer (about 25 μm between two microcracks; Webb et al .…”