Tomb No. 2 of Tushan in Xuzhou is the tomb of King Chu of the Eastern Han Dynasty, and it was an important archaeological discovery in China. The unique placement and crafting techniques of a lacquer coffin that was unearthed from the burial corridor are of significant importance in the study of tombs. In order to characterise the sample’s microstructure, elemental composition, and structural composition, as well as to study the crafting techniques of the coffin in the corridor, a range of analytical techniques were employed, including ultra-depth microscopy, scanning electron microscopy with SEM-EDS, Raman spectroscopy, FTIR, and XRD. The results indicate that the cross-sectional structure of the fragments comprises a pigment layer and a lacquer ash layer, with the latter being further divided into tile ash and bone ash layers. No lacquer film layer was observed. The primary colouring agent in the pigment layer was HgS, which contained a minor quantity of organic binder. The primary component of the tile ash layer was quartz, while the osseous ash layer comprised particles and collagen derived from mammalian bones. The lacquer crafting technique employed in the construction of the coffin was relatively simple and inconsistent with the assumption of it having a noble status. The findings of this research offer experimental data for the identification, preservation, and technical restoration of the corridor coffin in the future.

In the conservation of cultural relics, the application of Paraloid B72 in humid environments frequently results in the surface whitening of artifacts, which impairs their appearance and conceals important details. This study investigates the mechanisms underlying this phenomenon by examining the effect of ambient humidity, Paraloid B72 mass concentration, solution addition volume, and solvent type. To evaluate the microstructure, transmittance, and composition of the films, a range of analytical techniques were employed, including optical microscopy, scanning electron microscopy, a UV-Visible Spectrophotometer, and Fourier transform infrared spectroscopy. The findings indicate that higher ambient humidity, lower Paraloid B72 mass concentration, smaller solution addition volume, and solvents with higher volatility and water miscibility increase water content during curing, intensifying the whitening effect. These factors modify the interaction between water and solvent, altering the surface structure of Paraloid B72. The whitening mechanism is linked to the cooling effect of solvent volatility, which lowers the dew point temperature at the air–solution interface, causing moisture condensation. Moisture forms droplets that leave irregular pores upon volatility, resulting in surface roughness, optical heterogeneity, and a reduced refractive index, resulting in whitening. This study provides a theoretical basis for understanding and preventing the whitening of Paraloid B72.