Study on the pigments of Chinese architectural colored drawings in the Altar of Agriculture (Beijing, China) by portable Raman spectroscopy and ED-XRF spectrometers

Abstract

The in-situ measurement was carried out on the pigments used in the colored drawings in the Altar of Agriculture (Beijing, China) for the first time by portable Raman and ED-XRF spectrometers. Three kinds of colored drawings (the original drawing, the restored drawing, and the repainted drawing) located in Sacrificial Storehouse were studied. The information of the pigments, including red lead, white lead, indigo, carbon black, and atacamite were found in the original drawing, while Bright red β-naphthol, Sudan Ⅰ, chrome yellow, titanium dioxide, ultramarine blue, and phthalocyanine green were identified from the repainted drawing. Chrome yellow, ultramarine blue, and phthalocyanine green were used in the green and blue regions of the restored drawing. According to the application history of the pigments and the records of the Altar of Agriculture, the original colored drawing could be dated to the Qianlong period. The pigments used in restoration and repaint hadn’t followed up the original drawing. The main reason is a lack of knowledge about the pigments used in the original painting. Hence, the information of the pigments used in these original drawings is of great guiding significance for the subsequent protection and restoration of the architectural drawings in Altar of Agriculture (Beijing, China).