This color contains the following pigments:
polychlorinated copper(II) phthalocyanine
C32H3Cl13CuN8 to C32HCl15CuN8 or C32H16CuN8Cl15 (PG7) or C32Br6Cl10CuN8 (PG36)
Phthalo Green is a transparent, cool, bright, high intensity color used in oil and acrylics. It comes from a Phthalocyanine Blue pigment where most of the hydrogen atoms have been replaced with chlorine, forming highly stable molecules. It has similar pigment properties and permanence to Phthalo Blue. It is slow drying and an excellent base color for mixing a range of bright greens. Phthalo Green is considered a very good alternative to Viridian because it is intense and mixes well and can be used to emphasize mineral colors in various tints. However, its tinting strength is very high, so it can overpower other colors. This pigment most closely resembles the discontinued and toxic Verdigris.
Phthalo Greens are completely lightfast and resistant to alkali, acids, solvents, heat, and ultraviolet radiation. They are currently used in inks, coatings, and many plastics due to their stability and are considered a standard pigment in printing ink and the packaging industry.
Phthalo Green has no significant hazards, but it contained PCBs (polychlorinated biphenyls) until 1982.
This bright blue-green was developed in 1935 and has been in use since 1938.
organic, monoazo benzimidazolone
Benzimidazolone Brown is a transparent brown pigment that is heavily staining and dark valued but has moderately low tinting strength. According to its manufacturer Clariant, “It is a dark brown, very transparent benzimidazolone pigment with excellent light, weather, and solvent fastness properties plus high heat stability. Recommended for paste inks, solvent and water based packaging gravure, and flexographic printing inks.” Benzimidazolone Brown has been used in watercolor painting, where transparent brown colors have traditionally been mixed from other pigments.
Benzimidazolone Brown has excellent lightfastness and weather resistance.
Benzimidazolone pigments were developed and patented by Hoechst in 1960, and have gradually come into use as artist pigments.