How photobleaching affects water colors when graphic works are being restored

摘要

Experiments have been carried out with thirty-six watercolor samples on paper, fabricated by the Leningrad Factory of Art Paints in 1964 to study processes of photobleaching by the radiation of fluorescent lamps. The color characteristics are determined in the CIE XYZ and CIE L*a*b* colorimetric systems, and the color difference and the change of the brightness, hue, and saturation of the samples are calculated. It is established that the results have little connection with the color-stability characteristic of the pigment but depend mainly on the capability of the paints to be washed away. Of the watercolor samples investigated here, twelve showed virtually no change after photobleaching.