Medieval experiments yielded vivid pigments like vermilion, mosaic gold, and verdigris—all found in these books. The Alchemy of Color and Chemical Change ... by The J. Paul Getty Museum
Pigments mixed with oil look glossy, whereas those mixed with egg yolk appear matte and flat even when layered. Making Green: Tempera versus Oil by The National Gallery, London
How can paint ingredients be identified? Scientists examine tiny samples and prepare pigments from old recipes. Making Purple: The Science of Art by The National Gallery, London