Sennelier Artists' Extra Fine Oil Paint - Chromium Green Deep, 40 ml tube

Pigment Information

This color contains the following pigments:

PY154-Benzimidazolone Yellow

PB27-Hooker’s Green

PG7-Phthalo Green

Pigment Name

PY154-Benzimidazolone Yellow

Pigment Type

monoazo

Properties

Benzimidazolone Yellow is a pigment with dull tints and an average drying time.

Permanence

Benzimidazolone Yellow has excellent lightfastness.

Toxicity

Benzimidazolone Yellow is not considered toxic.

History

The benzimidazolone group of pigments was developed and patented in 1960 by Hoechst A.G., a German chemical manufacturer that was a forerunner of the pharmaceutical company Aventis.

Pigment Name

PB27-Hooker’s Green

Pigment Type

mix of organic pigments

Chemical Formula

C30H18FeN3O6Na

Properties

Hooker’s Green is a bright olive-green often sold in a yellowish shade and a bluish shade. Its transparency can range from dull and dark to bright and light because lightness and chroma vary based on manufacturer. Modern varieties have a rich, dark tone that provides a great range when mixing. Hooker’s Green is particularly good for landscape painting when a larger range of foliage is required. Dioxazine Violet is the best mixing compliment in watercolor form.

Permanence

The permanence and lightfastness of Hooker’s Green varies by brand. As a composite pigment historically mixed from Prussian Blue and Gamboge, its permanence is only fair. Modern replacements for Hooker's Green tend to be mixed with components that have more permanence, such as Phthalocyanine Green, Burnt Umber, and sometimes Hansa or Cobalt Yellow.

Toxicity

Hooker’s Green can be hazardous, but the toxicity level depends on the specific pigments used by each individual manufacturer or brand.

History

This pigment was originally an unreliable mix of Prussian or Iron Blue and Gamboge. Later, it became a more reliable mix of Cadmium Yellow and Phthalo Blue or Green. It was a staple green for 19th century landscape and botanical painters. Most modern Hooker’s Green paints are yellow greens with a hue angle around 140, or a mix of Phthalo Green and Burnt Umber.

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.