Color Swatch created using heavy application/medium application/50% tint and was applied on acrylic primed canvas (7 oz) material.
This color contains the following pigments:
PR170—Naphthol Red
Pigment Type
organic, naphthol AS
Chemical Name
n/a
Chemical Formula
C26H22N4O4
Properties
Pigment PR170 is a bright deep red with bluish undertones. It has an average drying time. It has two crystaline forms that differ significantly in opacity. The more transparent form (F5RK) tends to be more bluish and is less lightfast.
Permanence
The lightfastness and weatherfastness of Pigment PR170 varies, depending on the application and the crystaline form. The opaque form (F3RK) has very good lightfastness, and is more weather resistant. The transparent form (F5RK) has lightfastness that is considered acceptable in pure applications, but it fades more in tints. Neither form is considered suitable for exterior use.
Toxicity
Naphthol Reds are not considered toxic. They may cause eye, skin, or respiratory irritation. Contact with dry pigment should be avoided.
History
Naphthol pigments are actually dyes that are "laked" to form pigments. First developed by the German chemical company Hoechst A.G. before World War I, their use in artist paints began in the 1920s. Pigment Red PR170 is a Naphthol AS pigment, chemically related to the diarylide yellow pigments. The Naphthol AS pigments comprise a range of reds. They are used in plastics, textiles, and printing inks.
Alternate Names
Naphthal, Naphthol Bordeaux, Naphthol Carbamide, Naphthol Carmine, Permanent Carmine, Naphthol Crimson, Permanent Red, Permanent Red F3RK (more opaque), Permanent Red F5RK (more transparent).
PR149—Perylene Red
Pigment Type
organic, anthraquinone
Chemical Name
n/a
Chemical Formula
C40H26N2O6
Properties
Perylene Red is a moderately intense, semi-opaque, medium red pigment, appearing somewhere between a Cadmium Red and a Cadmium Deep Red hue. It has excellent brightness and tinting strength. Its partial transparency makes it useful as a glazing color.
Permanence
Perylene Red has good lightfastness and permanence. Its tints may darken after extended exposure to sunlight. It is not considered suitable for exterior use.
Toxicity
Perylene Red has no significant acute toxicity. Its long term hazards are currently unknown.
History
Perylenes have been used as vat dyes since 1912, but they were not manufactured and sold as pigments until 1957. For artists, they are a replacement for historic colors that were made with berries, and are significantly more lightfast.
Alternate Names
Perylene Scarlet
PR101—Red Iron Oxide
Pigment Type
earth, synthetic
Chemical Name
iron oxides (synthetic), iron oxide, silica, alumina, lime, and magnesia or hydrated iron oxide
Chemical Formula
Fe2O2 or Fe2O3 • H2O
Properties
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.
Permanence
Red iron oxide is very lightfast with excellent permanence.
Toxicity
Red iron oxide has no significant hazards.
History
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.
Alternate Names
Indian Red, Colcothar, English Red, Light Red, Mars Red, Mars Violet, Morelle Salt, Pompeian Red, Indian Red, Red Oxide, Sinopia, Spanish Red, Terra Rosa, Tuscan Red, Venetian Red, Venice Red.
PW6—Titanium White
Pigment Type
inorganic
Chemical Name
titanium dioxide
Chemical Formula
TiO2
Properties
Titanium White is the most brilliant of the white pigments. It is considered an all purpose oil color useful in all techniques and the best all around white. Its masstone is neither warm nor cool, placing it somewhere between Lead White and Zinc White. It is less prone to cracking and yellowing than Lead White, but it still yellows easily. Titanium White dries slowly in oil form, more slowly than Lead White but more quickly than Zinc White. It is opaque in oil and acrylic forms and semi-opaque in watercolor form. This pigment has good chemical stability, and its tinting strength is superior to both Lead White and Zinc White.
Permanence
Titanium White has excellent permanence and lightfastness.
Toxicity
Titanium dioxide is highly stable and is regarded as completely non-toxic. Animal studies give no indiciation that it is absorbed biologically, even after long periods of exposure. The primary safety concern is with inhalation of fine pigment dust particles. Titanium White, if inhaled in large amounts over the course of several years, may cause a benign pneumoconiosis that is visible on x-rays. The National Institute of Occupational Safety and Health (NIOSH) considers fine titanium dioxide particles, if inhaled, to be a human carcinogen. The primary concern for artists is to avoid exposure to fine particulate dust from raw pigments.
History
Titanium is the ninth most abundant element in the Earth's crust, however mineral deposits that are economical to mine are less common. Titanium dioxide was first discovered in 1821, although it could not be mass produced until 1919. Widespread use of the pigment began in the 1940s. Since that time, it has become the most commonly used white pigment. The name comes from the Latin word Titan, the name for the elder brother of Kronos and ancestor of the Titans, and from the Greek word tito, meaning day or sun.
Alternate Names
None.
