Originally extracted from the madder plant, and turned into a pigment by laking, its colour could fade within months. Later purified to alizarin it proved no better, and is now used as a measure of non-lightfastness.
Melone
In their original form as madder, derived from plants and poorly resistant to light. Refined to Alizarin Crimson, still fugitive, and a standard for fading. Finally fully ‘permanent’.
The Eclectic Light Company 