Blockx Soft Pastels are handmade in Belgium using pure pigments in the same tradition started by company founder and chemist Jacques Blockx in 1844. Pastels are soft and velvety in texture. Best-suited for use on pastel paper.
Color Swatch created using heavy to light application and was applied on 100 lb (163 gsm) drawing paper material.
Diarylide Yellow is a semi-opaque, moderately staining, intense deep reddish yellow pigment with good tinting strength.
Diarylide Yellow 83 has very good lightfastness and permanence. However, it can fade in tints, so some artists do not consider it suitable as an artists’ color. Many other diarylide yellow pigments are reported to have fair to poor lightfastness, and some are completely fugitive. Diarylide Yellow 83 is reputed to be one of the most permanent of the entire group.
Diarylide Yellow has no significant acute hazards, but chronic hazards have not been well studied.
Diarylide Yellow comes from a family of azo pigments called Diarylide. These yellow hued pigments were developed around 1940 and are very important in printing inks.
Benzidine Yellow, Diazo Yellow.
Bis-(p-chrolopheny)-1. 4-diketopyrrolo(3. 4-c)pyrrole
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.”
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.
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 sensitiser 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. On the basis of submitted data, the notified chemical would not be classsified as hazardous in accordance with Approved Criteria for Classifying Hazardous Substances."
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.
Magnacryl Red, Versal Red, Microlith Red, Unisphere Red, Cromophtol Red, Irgazin Red.
® Blockx is a registered trademark.