Evaluating the Reliability of Cross-Instrument Comparison: (p)XRF Measurements of Two Rare ‘Kangxi-Reign’ Enameled Glasses

The study of heterogeneous exceptional objects preserved in different places implies the use of various instruments. Here, we compare the manufacturing techniques of two rare enameled glasses (a box and a vase) made for the Kangxi Emperor (r. 1661–1722) using XRF analyses performed in the laboratory for one object and with a mobile spectrometer for the other. The enamels are identified and compared based on the characteristic signals of different chemical elements, with or without multivariate analysis. Although the bodies have similar compositions (but differ in trace elements) and are opacified with calcium arsenate, large differences are observed for certain enamels: the red of the box is obtained using the traditional Chinese method based on copper nanoparticles, while the brown and purple to pink of the vase use gold nanoparticles, a recipe imported from Europe. The white highlights of the box are opacified with tin. Cobalt is rich in arsenic and contains bismuth and nickel, consistent with European importation as reported in historical sources. Naples yellow is used in both objects. A comparison of the distinctive features of these objects with those of painted enameled imperial porcelain and cloisonné enamelware further highlights the technological exchanges and material choices involved in the production of imperial decorative objects, as well as the very innovative ‘research’ conducted at the imperial glass workshop.