Influence of illumination on inorganic pigments used in Chinese traditional paintings based on Raman spectroscopy

Taking colour difference as the damage indicator for evaluating light sources used for lighting Chinese traditional paintings means we can only judge the photochromic phenomenon, but cannot evaluate the mechanical damage such as cracking, cannot solve the problem that the material has been damaged without any colour change and cannot analyse non-staining cultural relics. In order to solve these problems, this study conducted a long-term illumination experiment on pigment specimens of Chinese traditional painting with light sources commonly used in museums. The Raman spectra of specimens before and after illumination were tested. By analysing the variations of Raman characteristic peak intensity ratios, the quantitative influence and relative influence coefficients of different light sources on the microscopic molecular structure of paintings were studied. Finally, the results of this study were compared with the results of previous research on colour, to determine whether the two sets of results were consistent which would verify the credibility of the research method adopted