Pigment

In biology, pigment is any color in plant or animal cells. Nearly all types of cells, such as skin, eyes, fur and hair contain pigment. Creatures that have deficient pigmentation are called albinos.

In the coloring of paint, ink, plastic, fabric and other material, a pigment is a dry colorant, usually an insoluble powder. There are both natural and synthetic pigments, both organic and inorganic ones. Pigments work by selectively absorbing some parts of the visible spectrum (see light) whilst reflecting others.

A distinction is usually made between a pigment, which is insoluble, and a dye, which is either a liquid, or is soluble. There is no well-defined dividing line between pigments and dyes, however, and some coloring agents are used as both pigments and dyes. In some cases, a pigment will be made by precipitating a soluble dye with a metallic salt. The resulting pigment is called a "lake".

List of pigments

Heme/Porphyrin based

• Chlorophyll
• Bilirubin
• Hemocyanin
• Hemoglobin

Light emitting

• Luciferin

Lipochromes

• Carotenoids
  • Alpha and Beta Carotene
  • Cyanins
    • Anthocyanin
  • Lycopene
  • Rhodopsin
  • Xanthophylls
    • Canthaxanthin
    • Zeaxanthin
• Lutein

Photosynthetic

• Chlorophyll
• Phycobilin

Other

• Hematochrome
• Melanin
• Pthalocyanine blue
• Urea

Painting pigments

• Alizarin
• Cadmium pigments
• Carbon black
• Cerulean blue
• Cobalt pigments
• Crimson
• Fugitive pigments
• Indigo dye
• Lead pigments
• Mars black
• Prussian blue
• Red ochre
• Sienna
• Titanium dioxide
• Ultramarine
• Yellow ochre
• Zinc white

External link

Pigments through the ages