Non-destructive identification of pigments printed on six Imperial China Engraved Coiling Dragon stamps.

Raman spectroscopy was employed to investigate six Imperial China Engraved Coiling Dragon stamps non-destructively. The results have shown that (1) the main colors (yellow, green, scarlet, brown, vermilion, and blue) on the six stamps were all prepared from inorganic pigments, including chrome yellow, chrome orange, Prussian blue, red lead, magnesium sulfate hydrate, and ultramarine blue. (2) Raman spectrometer has been allowed for successfully identifying the molecular structure of the pigments printed on the six examined stamps, suggesting that such a dual analytical approach could satisfy the need for pigment identification on stamps. (3) The finding that certain pigments were intentionally mixed to produce a whole different hue or color, the mechanism of which could be explained by theories of chromatology and metamerism, also provides new insight into the future conservation, authentication, and restoration of the early printings. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]