Alizarin

Originally a bright red pigment, also called madder lake, made from madder, derived from the root of the plant Rubia tinctorum. Alizarin now generally refers to a pigment and a class of dyes derived from anthraquinone ? synthetic coal-tar ? and is used in the manufacture of blue, brown, green, red, violet, and yellow pigments.Related resource: Pigments through the Ages on Madder lake (alizarin).