Holbein Irodori Artist Gouache - Vermillion, 15 ml, Tube

Pigment Information

This color contains the following pigments:

PY74-Hansa Yellow

PO73-Transparent Pyrrole Orange

PR254-Pyrrole Red

Pigment Name

PY74-Hansa Yellow

Pigment Type

monoazo

Chemical Formula

C18H18N4O6

Properties

Pigment PY74 is one of the most commercially important pigments of the Hansa Yellow group, considered superior to many others in its class based on both tinting strength and lightfastness. Several PY74 grades with different particle sizes are available. Grades with finer particle size are more brilliant and transparent. Pigment PY74 ranges from reddish yellow to greenish yellow, with temperature shifts from cool to warm hues. It has high tinting strength and average to slow drying time.

Permanence

This Hansa Yellow has better lightfastness that other yellow monoazo pigments, particularly in the darker shades.

Toxicity

Hansa Yellow has no significant acute hazards, though its chronic hazards have not been well studied.

History

Hansa Yellows were first made in Germany just before WW1 from a series of synthetic dyestuffs called Pigment Yellow. They were intended to be a synthetic replacement for Cadmium Yellow.

Pigment Name

PO73-Transparent Pyrrole Orange

Pigment Type

organic, aminoketone

Chemical Name

dipyrrolopyrrol

Properties

Transparent Pyrrole Orange is a yellow-shade orange with optimum performance; high saturation and excellent durability, excellent bleed resistance, and intrinsic strength coupled with good opacity and moderate rheology. It is semi-opaque, less opaque than Cadmium Orange.

Permanence

Transparent Pyrrole Orange has been demonstrated to have excellent stability and lightfastness in automotive applications.

Toxicity

The Australian government's Department of Health and Aging, reported in its Summary Report: NA/238 that "Irgazin DPP Orange 16AOA is likely to be of low oral and dermal toxicity in humans and to be non irritating or very slightly irritating to the ey

History

Irgazin Orange was developed as a lead-free alternative opaque orange pigment. It is used in decorative, industrial, and automotive applications, often to color plastics and polymers.

Pigment Name

PR254-Pyrrole Red

Pigment Type

organic, aminoketone

Chemical Name

Bis-(p-chrolopheny)-1. 4-diketopyrrolo(3. 4-c)pyrrole

Properties

Pyrrole Red is opaque and has strong covering power. According to manufacturer Ciba, which uses the trade name Irgazin Red, it is a “clean, highly saturated mid shade red with high temperature resistance, excellent color strength, outstanding chemical, solvent and bleed resistance, and good weatherfastness.”

Permanence

Pyrrole Red is considered to have excellent lightfastness among organic pigments in its class. Tests in industrial applications have given it scores of 7-8 on the Blue Wool Scale.

Toxicity

According to the Australian government's Ministry on Health and Aging, "The notified chemical exhibited low oral and dermal toxicity in rats, did not exhibit toxic effects when administered orally to rats for 28 days, was not a skin irritant in rabbi

History

Pyrrole Red, used as an automotive paint and as a colorant in plastics, was developed as one of a range of pigments to replace lead based pigments. In art materials, it is often used as a synthetic and lightfast replacement for carmine, a laked pigment that was originally produced from the body of the cochineal insect. It is also used to replace the older naphthol reds, organic red pigments that are sometimes only marginally lightfast and weatherfast.