Holbein Irodori Artist Gouache - Russet Green, 15 ml, Tube

Pigment Information

This color contains the following pigments:

PY17-Permanent Yellow

PG8-Hooker’s Green

PR83-Alizarin Crimson

Pigment Name

PY17-Permanent Yellow

Pigment Type

organic, disazo

Chemical Name

Benzidine Yellow GG

Properties

Pigment Yellow 17 is a somewhat greenish yellow that has very high tinting strength and good resistance to solvents.

Permanence

Pigment Yellow 17 has good lightfastness if prepared using the proper procedures. Because procedures for preparing PY17 vary, artists may want to conduct their own lightfastness tests to verify that the manufacturer has selected quality pigment.

Toxicity

Benzidine dyes are not bioavailable. Although benzidine-based dyes can be reduced to their amine precursors in vivo, creating a compound that is carcinogenic, benzidine dyes are believed to be so insoluble in water that they are unlikely to be absorbed in

History

This Benzidine Yellow dye was first reported by Esitelty in 1949. Initiailly, it was reported to be less lightfast than yellow monoazo pigments, which limited its usefulness. A method for making Pigment Yellow 17 more permanent was patented in 1972 (United States Patent 3785843), and the improved dye became known as Permanent Yellow. Permanent Yellow 17 is widely used in printing inks, textile dyes, paints, plastics, and coatings.

Pigment Name

PG8-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

PR83-Alizarin Crimson

Pigment Type

organic

Chemical Name

1,2-dihydroxyantraquinone

Chemical Formula

C14H8O4

Properties

Alizarin Crimson, the traditional cool counterpart to Cadmium Red, is a clear ruby-red with a maroon masstone and a bluish undertone. It is the artist's principal deep red pigment, is transparent, and has good tinting strength. It creates bright rosy pinks when mixed with white, a range of purples and violets when mixed with strong blues, can be slow drying when used with oils, and is compatible with all other pigments. Permanent Alizarin Crimson mixes well with Ultramarine in acrylic and watercolor form. Permanent Rose and Quinacridone Rose are possible alternatives on a watercolor palette. Alizarin Crimson is a popular glazing color.

Permanence

Alizarin Crimson is considered fugitive or marginally lightfast, and the appropriateness of its use in the modern artist palette is a subject of debate. There are many concerns regarding its permanence, particularly when mixed with ochre, sienna, and umber, or when used thinly. It is the least permanent red commonly used by today's artists. Modern synthetic preparations of Alizarin Crimson have better permanence and lightfastness that the original natural pigment, which was extracted from the madder plant. Quinacridone pigments have been used to create a modern hue that closely matches the original hue, but many artists object that the transparency and handling characteristics are not the same as for the original.

Toxicity

Alizarin Crimson can be slightly toxic if it comes into contact with skin and may cause some allergies. There is no significant acute toxicity.

History

The word alizarin comes from the Arabic word al-usara, meaning juice. The base ingredient of this pigment is the Madder plant (Rubia Tinctorum). It was used for dyes and inks among craftsmen in Ancient Persia, India, and Egypt as early as 1500 BC In 1804, George Field, an English dye maker, developed Madder Lake by binding madder to alum, a white powder. The German chemists Carl Grabe and Carl Liebermann produced the first synthetic variety of this pigment, most commonly known as Alizarin Crimson, in 1868. They used anthracene, which greatly improved the lightfastness. The Colour Index International designation PR83:1 has been used to identify this synthetic laked pigment.