Article by chemist Charles E. Pellew surveying the dyestuffs used in the Middle Ages and how they compare with those of antiquity and later periods. It covers yellows (saffron, Persian berry, iron rust), blacks (iron and tannin, galls, logwood), reds (kermes, lac, cochineal, madder), and blues (indigo and woad). Along the way it discusses mordants, fastness of colors, the fading of yellows and greens in old tapestries, the woad-versus-indigo controversy, and the arrival of synthetic indigo.