Synthetic organic colorant composed of copper phthalocyanine that was first synthesized in 1933; it was marketed as a paint pigment called Monastral blue. The organic colorant is usually adsorbed on an aluminum hydrate base to form a deep blue color. In industry, phthalocyanine blue has replaced all other blue pigments for use in coatings because it is lightfast as well as resistant to chemicals and clumping.
