PWC Extra Fine Professional Watercolor - Neutral Tint, 15 ml, Tube

Pigment Information

This color contains the following pigments:

PB66-Indigo

PBk11-Mars Black

Pigment Name

PB66-Indigo

Pigment Type

synthetic, organic

Chemical Name

2,2’-Bis(2,3-dihydro-3- oxoindolyliden)

Chemical Formula

C16H10N2O2

Properties

Indigo is a deep blue pigment, almost violet dye that can be laked as a pigment.

Permanence

Indigo is fugitive. Indigoid Blue is the famous blue dye used in many blue jeans and other denim products, famous for the way it fades! Although a few paint manufacturers offer a genuine indigo color based on PB66, it should be used only for applications that are not permanent, or where the color is required for historic reasons. Most paint manufacturers replicate this historic hue with other more permanent pigments.

Toxicity

Although natural indigo is known to be mildly toxic, its toxicity is believed to be the result of other natural alkoids found in plant sources, not of the indigo dye itself. The acute and chronic toxicity of synthetic indigo dyes has been studied and has

History

Indigoid Blue is a synthetic version of Indigo, a famous dye and laked pigment that has been used since ancient times. The chemical compound that constitutes the indigo dye is called indigotin. More than 30 species of plants, found in many parts of the world, can be used to produce indigo dye. Indigo dye became the rage in Europe during the late Middle Ages. Although genuine indigo from plant sources is available, only the synthetic version is now used in commercial dye and pigment products. Genuine Indigo is designated NB1 (Natural Blue 1). The synthetic dye molecule was first synthesized by Bäyer in 1878, and it later became available as a commercial dye, quickly replacing natural sources.

Pigment Name

PBk11-Mars Black

Pigment Type

earth

Chemical Name

iron oxides

Chemical Formula

FeO or Fe2O3

Properties

Mars Black is an opaque black with a strong and cool masstone, a slightly warm tint, and a warm brown undertone. It is not as black as Ivory Black, but it dries more quickly and has three times the tinting strength. Mars Black is normally the only black available in acrylic form and that is safe to over paint. It can be used in all media without reservation and is widely used as an alternative to Lamp Black and Ivory Black.

Permanence

Mars Black is very lightfast with excellent permanence.

Toxicity

Mars Black has no significant hazards and is the only major black pigment considered non-toxic.

History

The word Mars refers to the Roman god of iron and war. Mars Black was developed in the early 20th century from inorganic, synthetic iron oxide.