School of Arts and Sciences
Blue pigment were in short supply in medieval times because only two naturally-occurring inorganic blue pigments, natural ultramarine and azurite, were known. Both pigments were difficult to obtain and consequently were very expensive. Medieval artists turned to the manufacture of copper-based blue pigments of surprising complexity in order to expand their palettes. This paper outlines some of the methods used to obtain these complex pigments and elucidate their structures, when possible.
Orna, M. V. Copper-Based Synthetic Medieval Blue Pigments. In Archaeological Chemistry: Organic, Inorganic and Biochemical Analysis; Orna, M. V., Ed.; American Chemical Society: Washington, DC, 1996; 107-115.