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• Quantification of low-z boron in the glassy matrix of Chinese painted enamels. • Transfer of Jesuit borosilicate glass technology to Chinese enamelled copperwares. • Attribution of raw material source of boric oxide (B 2 O 3) through trace elements. • Compositional distinction between three enamel workshops in Beijing and Guangzhou. • Relationship between enamel composition and degradation phenomena. The white enamel surfaces of ten Chinese painted enamels dating to the Qianlong and Jiaqing periods (1736–1820) were studied with Laser Ablation Inductively Coupled Mass Spectrometry (LA-ICPMS). These enamels are opacified with lead arsenate, a dramatic change in technology from fluorite and lead stannite opacification used in Chinese and European enamels before the 18th century. The primary goal of this project was to test the hypothesis that boron is a significant component in Chinese painted enamels. Borax (Na₂[B₄O₅(OH)₄]·8H₂O) was used by glassmakers working in the imperial workshops in Beijing in the mid-18th century, and boron has been detected in some examples of Qing glass and enamels. Quantitative analyses of major, minor, and trace level elements were carried out with LA-ICPMS. Three compositional groups were identified by the amount of borax in the enamel: high borax (at 6.7% B 2 O 3), low borax (up to 1.3% B 2 O 3), and borax free. The results show that it is possible to distinguish between objects made in Beijing and Guangzhou through elemental analysis, and that there are two distinct compositional groups of Chinese painted enamel produced in Guangzhou during this period. [ABSTRACT FROM AUTHOR]