Sennelier Watercolour S2 Sennelier Red (636)

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 colour strength, outstanding chemical, solvent and bleed resistance, and good weather-fastness.

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 rabbits, was not a skin sensitizer in guinea pigs, was not mutagenic in bacteria and was not clastogenic in CHO cells in culture. However, the notified chemical was a slight eye irritant in rabbits. Based on the submitted data, the notified chemical will not be classified as hazardous per the Approved Criteria for Classifying Hazardous Substances."

History: Pyrrole Red, used as an automotive paint and a plastics colourant, was developed as one of a range of pigments to replace lead-based pigments. Art materials are often used as a synthetic and lightfast replacement for carmine, a laked pigment initially 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 weather-fast.

Alternate Names: Magnacryl Red, Versal Red, Microlith Red, Unisphere Red, Cromophtol Red, Irgazin Red.