Great American Handmade Pastel - Dorian 4, 220.4

Product Details
- Description:
- Pastel
- Color:
- Dorian 4
- No.
- 220.4
Pigment Information
This color contains the following pigments:
PW18-Calcium Carbonate
PBk28-Black Spinel
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.
Pigment Name
PBk28-Black Spinel
Pigment Type
inorganic
Chemical Name
copper chromite black
Chemical Formula
Properties
Black Spinel is a very neutral opaque black pigment, excellent for tinting to create neutral grays.
Permanence
Black Spinel has excellent lightfastness.
Toxicity
Black Spinel is mildly toxic. The pigment itself has an extremely fine particle size. It causes irritation and ulceration to skin. Respiratory exposure and exposure to dust are serious concerns.
History
Black Spinel is much more expensive than carbon-based blacks. Its use as a pigment has been limited to applications where a truly neutral black or gray tone is needed.