A multi-analytical approach to investigate date-unknown paintings of Chinese Taoist priests

摘要

This article presents a technical investigation into a set of four artist- and date-unknown paintings of Chinese Taoist priests, which aimed to reveal their fiber source, painting technique, starch-based adhesive, and pigment use for the purpose of future conservation treatment. By using an integrated approach (Herzberg staining, cross-sectioning, starch grain analysis, X-ray fluorescence, Raman spectroscopy, and X-ray diffraction), it turned out clear that (1) bamboo was the primary (if not the only) fiber source; (2) multiple layers were utilized in combination with simply outlining and filling, while paintings were in preparation; (3) wheat flour, a starch-based adhesive, was used to hold together the painting paper and the paper supports underneath; and (4) vermilion, emerald green, synthetic ultramarine blue, orpiment, lead white, and carbon black were used to produce the six main colors on the paintings. The discoveries of emerald green and synthetized ultramarine blue placed the earliest possible manufacturing dates of these paintings around the 1830s.