Holbein Artists' Oil Color - Bright Red, 20 ml tube

Pigment Information

This color contains the following pigments:

PR188 -Naphthol Red

PR48:2-Ruby Red

Pigment Name

PR188 -Naphthol Red

Pigment Type

organic monoazo

Chemical Formula

C33H24Cl2N2O6

Properties

This Naphthol Red is yellowish, with a high tinting strength and average drying time. It produces warmer shades and tints.

Permanence

This Naphthol Red has excellent lightfastness, though it is generally not considered adequate 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 Name

PR48:2-Ruby Red

Pigment Type

organic, monoazo

Chemical Name

beta-oxynaphthoic acid lake, calcium salt

Properties

Ruby Red is a common name used for the calcium salt of beta-oxynaphthoic acid (BONA) lake pigment PR:48. It is substantially bluer than other shades of PR:48. BONA pigment lakes have high tinting strength.

Permanence

Beta-oxynaphthoic acid (BONA) lake pigments are more lightfast than their beta-naphthol counterparts. Although their lightfastness makes them the pigment of choice in many applications, they may shift slightly in color or lose intensity under some conditions.

History

Ruby Red is a lake pigment of beta-oxynaphtholic acid, a dye that resembles the common beta-Naphthol pigments. Beta-oxynaphthoic acid may have been synthesized as early as 1887. Commerical use of BONA lake pigments began in the 20th century. Ruby Red is used in printing and plastics.