Great American Handmade Pastel - Aubergine 0, 240.0

Pigment Information

This color contains the following pigments:

PBk11-Mars Black

PR122-Quinacridone Magenta

PW18-Calcium Carbonate

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.

Pigment Name

PR122-Quinacridone Magenta

Pigment Type

organic, quinacridone

Chemical Formula

C22H16N2O2

Properties

Quinacridone Magenta is a semi-transparent and powerful bluish red with an impressive mixing range. It makes an excellent glazing color and is one of the bluest of the Quinacridone colors. The pigment's properties vary considerably, depending on how it is ground. Quinacridone pigments have relatively low tinting strength in general. For this reason, quinacridone colors are often expensive, because more pigment is required in the formulation.

Permanence

Quinacridone Magenta offers very good lightfastness in most media, but some have argued that it is less lightfast in watercolor form. Although Quinacridone Magenta received only a passing grade of "fair" under ASTM test protocols, other test results have rated the pigment very good to excellent. Transparent reddish violet pigments in general have more problems with lightfastness than any other range of colors. PR122 is often used as the Magenta of CMYK (four color) process printing because it offers a better tradeoff between tinting strength and lightfastness than other pigments in its class.

Toxicity

Quinacridone Magenta has no acute hazards. Overexposure to quinacridone pigments may cause skin irritation. Quinicridone pigments contain a compound found to be a skin, eye, and respiratory irritant.

History

Quinacridone Magenta came from a red violet aniline dye that was first produced in 1858 by Natanson. It was called Magenta to commemorate a battle in Magenta, Italy. Over time, Magenta became the standard color name for a deep, violet red. Although quinacridone compounds became known in the late 19th century, methods of manufacturing so as to make them practical for use as commercial pigments did not begin until the 1950s. PR122 has become particularly popular in the formulation of Magenta for CMYK process printing.

Pigment Name

PW18-Calcium Carbonate

Pigment Type

inorganic

Chemical Name

calcium carbonate

Chemical Formula

CaCO3

Properties

Calcium carbonate, the mineral constituent of chalk, is a low tinting strength, inexpensive white pigment that is often used is a buffer and filler. Because of its low tinting strength, it is overwhelmed by other colors. It is used in gesso and other coatings to give the surface more tooth, a desirable characteristic for some painting techniques.

Permanence

Calcium carbonate is lightfast. Like all carbonates, it reacts with strong acids

Toxicity

Calcium carbonate is completely non-toxic, and is used in many food, cosmetic, and pharmaceutical products. However, excessive consumption is not recommended. 

History

Naturally occuring chalk deposits have been mined since prehistoric times. Rocks and minerals that contain calcium carbonate include aragonite, calcite, vaterite, chalk, limestone. marble, and travertine. Calcium carbonate is the principle component of lime, used in many agricultural and industrial applications.