Due to differences in users’ monitors, the colors presented are an approximation of the true color.
PR254-Pyrrole Red
PR101-Red Iron Oxide
PB15-Phthalo Blue
PR254-Pyrrole Red
organic, aminoketone
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.
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.
PR101-Red Iron Oxide
earth, synthetic
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.
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.
PB15-Phthalo Blue
organic
copper phthalocyanine
C32H16CuN8
Phthalo Blues are pure and clean primary blues with superior covering power. They have a very high tinting strength and tend to overwhelm other pigments, but if color strength can be controlled, they make predictable mixed colors. In oil form, blues are very deep and slow drying. When mixed with other colors or if chlorine is added, Phthalo Blue quickly tends towards green. When using alone, mix with some white, as Phthalo Blue can be semi-transparent and almost black on its own. It is among the most compatible of modern colors with mineral colors and is considered more reliable than Prussian Blue, while sharing the same physical and color properties. Phthalo Blue is a good color for glazing.
Phthalo Blues are completely lightfast and stable and are permanent for all paint uses. They are currently used in inks, coatings, and many plastics due to their stability and are considered a standard pigment in printing ink and the packaging industry.
Developed by chemists using the trade name Monastral Blue, the organic blue dyestuff now known as Phthalo Blue was presented as a pigment in November 1935 in London. Its discovery was accidental. The dark color was observed in a kettle where a dye was being made from a British dyestuff plant. The demand for such a pigment came from commercial printers who wanted a cyan to replace Prussian Blue.