Fig. 7From: Applying micro-computed tomography (micro-CT) and Raman spectroscopy for non-invasive characterization of coating and coating pigments on ancient Chinese papersRaman spectra of (a) beeswax identified on Lajian QY, b modern natural beeswax, c kermesic acid as a red dye on Lajian QP, and d purpurin as a possible red dye on Lengjinjian QRBack to article page