Phthalocyanine Blue BN, also called phthalo blue, helio blue, thalo blue, Winsor blue, phthalocyanine blue, C.I. Pigment Blue 15:2, Copper phthalocyanine blue, Copper tetrabenzoporphyrazine, Cu-Phthaloblue, PB-15, PB-36, and C.I. 74160, is a bright, greenish-blue crystalline synthetic blue pigment from the group of phthalocyanine dyes.
It was first developed as a pigment in the mid-1930s. Its brilliant blue is frequently used in paints and dyes. It is highly valued for its superior properties such as light fastness, tinting strength, covering power and resistance to the effects of alkalies and acids. It has the appearance of a blue powder, insoluble in water and most solvents.
A common component on the artist's palette, Phthalo Blue is a cool blue with a bias towards green. It has intense tinting strength and easily overpowers the mix when combined with other colors. It is a transparent staining color and can be applied using glazing techniques.
Due to its stability, phthalo blue is also used in inks, coatings, and many plastics. The pigment is insoluble and has no tendency to migrate in the material. It is a standard pigment used in printing ink and the packaging industry.
Phthalocyanine Blue BN is also used as a source material for manufacture of Phthalocyanine Green G.