Analysis of an Ancient Architectural Painting from the Jiangxue Palace in the Imperial Museum, Beijing, China

The Jiangxue Palace is part of the imperial garden of the Imperial Museum, a world cultural heritage site. In this work, the techniques and components of its color paintings are described and analyzed. The color painting represented a significant architectural component in the Ming and Qing dynasties. This paper analyzes the structure relationship of color painting, morphology, pigment composition, pigment crystal characteristics, and the composition of binder and filler in the plaster by using ultra-depth three-dimensional microscopy, polarized light microscopy, scanning electron microscopy-energy dispersive spectrometry, micro-Raman spectroscopy, X-ray diffraction, Fourier transform infrared spectrometry, and pyrolysis–gas chromatography–mass spectrometry. The Jiangxue Palace paintings are composed of multi-layered structures using pigments such as emerald green, lead white, and lead red (minium). The cross-sections of each structure are composed of a pigment layer (green and white), plaster (albite, anorthite, calcite, tung oil, and flour), and an underlying base of red minium. This research is conducive to a comprehensive understanding of the production technology of the Jiangxue Palace color paintings. The results provide a basis for the subsequent protection and repair of this valuable world cultural heritage site.