Holbein Artists' Watercolor Half Pan - Sap Green

Pigment Information

This color contains the following pigments:

PY180-Benzimidazolone Yellow

PG7-Phthalo Green

Pigment Name

PY180-Benzimidazolone Yellow

Pigment Type

organic, benzimidazolone

Chemical Formula

Properties

Benzimidazolone Yellow 180 is a transparent greenish yellow pigment with high tinting strength. It is very similar in hue to PY74, a Hansa Yellow pigment with even higher tinting strength that was the traditional yellow used in CMYK (four color) process printing.

Permanence

Pure tones of Benzimidazolone Yellow 180 have excellent lightfastness. Tints with white are considered less lightfast. Benzimidazolone Yellow 180 is considered to have greater lightfastness than PY74, which it often replaces in printing technology.

Toxicity

Benzimidazolone Yellow 180 is not considered toxic.

History

Benzimidazolone pigments were developed by Hoechst in the 1950s and 1960s. Benzimidazolone Yellow 180 is used in printing and plastics. Although it is more expensive than PY74, a Hansa Yellow, and has lower tinting strength, its lightfastness often makes it the yellow of choice in four color process printing.

Pigment Name

PG7-Phthalo Green

Pigment Type

organic

Chemical Name

polychlorinated copper(II) phthalocyanine

Chemical Formula

C32H3Cl13CuN8 to C32HCl15CuN8 or C32H16CuN8Cl15 (PG7) or C32Br6Cl10CuN8 (PG36)

Properties

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.

Permanence

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.

Toxicity

Phthalo Green has no significant hazards, but it contained PCBs (polychlorinated biphenyls) until 1982.

History

This bright blue-green was developed in 1935 and has been in use since 1938.