This color contains the following pigments:
PR101-Red Iron Oxide
1,4-diketo-3,6-di(4'-tertiary butyl phenyl)-2,5-dihydro pyrrolo[3,4-c]pyrrole
This bluish red transparent pigment has high tinting strength. Diketo pyrrolo pyrrole pigments are noteworthy for their light stability, excellent weatherability, and outstanding heat stability.
Pyrrole Rubine has excellent permanence and lightfastness for an organic pigment in its color range.
Pyrrole pigments are considered to be non-toxic.
The Pyrrole group of synthetic organic pigments was developed in the 1980s. Pyrrole Rubine was first manufactured by Ciba Specialty Chemicals under the trade name Irgazine Ruby. Although not a perfect match for alizarin crimson, Pyrrole Rubine is one of several new pigments that has helped to close a traditional gap in the gamut of artist pigments, the lack of lightfast and transparent colors in the red/blue and red/violet parts of the spectrum.
PR101-Red Iron Oxide
iron oxides (synthetic), iron oxide, silica, alumina, lime, and magnesia or hydrated iron oxide
Fe2O2 or Fe2O3 x H2O
Red iron oxide varies in hue and transparency, depending on hydration and slight impurities. Indian Red is a slightly duller, deep brick hue with a bluish undertone. It is very dense and opaque, with excellent tinting strength and covering power. It is dependable when mixing with all other permanent pigments and yields good flesh tints when mixed with Zinc White. It is the synthetic version of PR102, which is a pigment made from earth reds, or natural red iron oxides, and the names applied to PR101 and PR102 often overlap. The synthetic red iron oxides have mostly replaced natural red iron oxides and are brighter, stronger, finer, and more permanent. Indian Red is the highest grade bluish shade. Light Red, English Red, and Venetian Red are yellowish shades. Mars Violet is a dull and subdued bluish or purplish oxide.
Red iron oxide is very lightfast with excellent permanence.
Red iron oxide has no significant hazards.
Natural red iron oxide comes from the mineral ore hematite, called bloodstone by the ancient Greeks from the word hema, meaning blood. It is one of the oldest pigments, has been used by every major civilization, and was an important mineral for medieval alchemists. It was not widely used in artists' materials until the 17th century and was not produced in large quantities until the 18th century.