Schmincke Horadam Artist Gouache - Neutral Gray, 15 ml tube

Pigment Information

This color contains the following pigments:

PR251-Pyrazoloquinazolone Scarlet

PG7-Phthalo Green

PB60-Indanthrene Blue

Pigment Name

PR251-Pyrazoloquinazolone Scarlet

Pigment Type

organic

Properties

Pyrazoloquinazolone Scarlet is a semi-opaque, staining pigment that is a brilliant scarlet red, and has high tinting strength.

Permanence

Pyrazoloquinazolone Scarlet has excellent lightfastness.

Toxicity

Pyrazoloquinazolone Scarlet has no acute toxicity.

History

Pyrazoloquinazolone Scarlet is a contemporary substitute for Vermilion, a pigment that contains toxic mercuric sulfide.

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.

Pigment Name

PB60-Indanthrene Blue

Pigment Type

organic, vat dyes

Chemical Name

complex, insoluble anthraquinone

Chemical Formula

C28H14N2O4

Properties

Indanthrene Blue is a clear, clean, deep blue organic pigment. It has moderate to high tinting strength and is not as overpowering as Phthalo Blue. Hansa Yellow Deep, Benzimidazolone Orange, and Raw Umber are its best mixing complements.

Permanence

Indanthrene Blue is permanent with excellent lightfastness in both masstone and tints.

Toxicity

Indanthrene Blue varies in its acute toxicity, though toxicity is generally slight.

History

Indanthrene Blue is the oldest vat dye, discovered and patented in 1901 by Rene Bohn. It is considered the first anthraquinone vat dye, a group of dyes characterized by excellent lightfastness. The pigment originates from this dye.