Rheotech Acrylics offer an excellent balance of quality and economy for the beginning artist and art student, with a full palette of 33 vibrant colors that provides teachers and students with the necessary tools for color theory and mixing.
Color Swatch created using heavy application/medium application/50% tint and was applied on acrylic primed canvas (7 oz) material.
organic, naphthol AS
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.
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.
Naphthol Reds are not considered toxic. They may cause eye, skin, or respiratory irritation. Contact with dry pigment should be avoided.
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.
Naphthal, Naphthol Bordeaux, Naphthol Carbamide, Naphthol Carmine, Permanent Carmine, Naphthol Crimson, Permanent Red, Permanent Red F3RK (more opaque), Permanent Red F5RK (more transparent).
C18H12N2O6, sodium salt
Lithol Rubine is a deep transparent red dye, generally slightly bluish, that is laked as a salt with sodium or calcium to form a pigment. PR57 is the sodium salt, and has a more bluish tone. PR57:1 is the calcium salt, and is the most widely used. Lithol Rubine makes clean pinks when tinted. Sources vary greatly in hue and transparency. Lithol Rubine has high tinting strength.
Lightfastness is considered only fair to good. Superior products are available when lightfastness is paramount. Where greater lightfastness is needed in process color printing, the more expensive pigment PR184, a Naphthol AS pigment, is often substituted for Lithol Rubine.
Lithol Rubine is not considered toxic. It is used in food, drugs, and cosmetics, such as lipstick. It can be used in art materials intended for children.
Lithol Rubine pigments (especially the calcium salt PR57:1) are widely used in inks, paints, plastics, and textiles. Lithol Rubine is widely used as magenta in process color printing.
4B Toner, Pigment PR57:1 is also known as D&C Red No 7, Ruby Red, Brilliant Carmine.
™ Rheotech is a trademark.