This color contains the following pigments:
monoazo, organic synthetic
Benzimidazolone Red is a transparent, dull, yellowish red with an average drying time. It lacks the color, purity, and brightness characteristic of most organic synthetic pigments.
Benzimidazolone Red has excellent lightfastness.
Benzimidazolone Red is not considered toxic.
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.
Dioxazine Violet is transparent and has very high tinting strength. It is a staining pigment, very dark valued when it is used at full strength. Concentrated, it paints out nearly black, but it mixes with Titanium White to form bright, opaque tints of purple. Pigment PV23 produces slightly redder shades than PV37. Because the hue can vary with the conditions of preparation and grinding, it may be offered in red shade, blue shade, and so forth. PV23RS is a preparation of PV23 that tends to reddish hue.
Dioxazine Violet has good lightfastness. There may be some concern about it fading or shifting in color in tints and washes. Some artists have reported that PV37, a molecular variant, is more lightfast than PV23.
Two molecular variants of Dioxazine Violet, PV23 and PV37, are available. They have similar properties, but mix slightly differently.