alizarin crimson definition

Alizarin crimson is a brilliant, clear, red lake pigment that features a bluish undertone with a maroon mass value.  The pigment is produced from dihydroxy anthraquinone, a coal-tar substance.  Alizarin crimson is suitable for permanent painting uses as long as the standard conditions for preserving a piece of artwork are followed. This is despite the face that it does not completely fit in the category of absolute permanence of furnace-made mineral pigments.  The pigment shows as a ruby-red when used transparently; and when combined with white pigment, beautiful and brilliant pinks can be created.  Moreover, the pigment can be combined safely with other pigments that are listed as safe for its mixture use.  The paint will retain its pigmentation when combined with iron-bearing colors so artists do not need to be concerned the pigment will become brown.  C. Liebermann and C. Graebe, both German chemists, are credited with discovering it; the pigment is ranked as the first of natural dyestuffs to be synthesized.  In time, their version of alizarin was used more in textile dyeing and the producing of the alizarin pigment than the the natural version of it.  Also, gradually alizarin crimson was used instead of madder lake, having a stronger tinting capability, and because it does not contain purpurin (an impermanent substance). Artists may combine sepia with alizarin crimson to create Roman sepia.  The term alizarin crimson was once known as alizarin carmine.