Shedding new light on lacquering crafts from the Northern Wei Dynasty (386–534 CE) by revisiting the lacquer screen from Sima Jinlong's Tomb

In this study, a suite of analytical techniques, including optical microscopy (OM), scanning electron microscopy - energy dispersive spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy (RS), X-ray diffraction (XRD), and pyrolysis - gas chromatography / mass spectrometry (Py-GC/MS) was employed to meticulously examine the lacquer screen excavated from Sima Jinlong's Tomb. The findings reveal a complex structure comprising multiple layers: a wooden core, two lacquer ash layers separated by a fabric layer, a primer layer, a red lacquer layer, and an outermost paint layer. Within the paint layer, orpiment, carbon black, and gypsum, with the green hue deriving from an unusual mixture of orpiment, indigo, and cinnabar - a composition rarely seen in lacquerware were identified. The study highlights the use of urushiol in the lacquer, with cinnabar added to the red lacquer layer, and ramie used in the fabric layer. Notably, the lacquer ash layer also contained hematite, in addition to previously recognized components such as bone ash, porcelain powder, and charcoal powder, marking a novel finding that has been less explored in earlier research. Through analyzing the lacquering techniques, namely Wanqi (垸漆), Buqi (布漆), Caoqi (糙漆), and Miaoqi (描漆) as documented in the Xiushilu (髹饰录), our research sheds light on the intricate lacquering processes and offers valuable insights for the conservation and restoration of such artifacts.