Organic dyes in Byzantine and post-Byzantine icons from Chalkidiki (Greece)

The present study is probably the first attempt to record the organic colouring materials found in Byzantine and post-Byzantine icons, made in the Mount Athos area and in the adjacent area of Chalkidiki. Fifteen icons, dated from the 14th to the 19th century were tested by Optical Microscopy (OM), employed to reveal the existing pigment layers and High Performance Liquid Chromatography (HPLC) combined with spectrophotometric UV-Vis detection, used for dyestuff identification. OM showed that organic dyes had been applied either as exclusive colouring materials or in combination with inorganic pigments. HPLC results showed that reddish cochineal and a “soluble” redwood appear to be the most common organic dyes of the icons tested. The limited use of madder, found only in one icon, suggests that the widespread plants of the Rubiaceae family were probably not frequently used by the iconographers during the historical period investigated. Similarly, an indigoid dye source was found in one sample. The results show that mixtures of organic dyes were used in Byzantine and post-Byzantine icons.