Pigmentation
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
Light emitting
Photosynthetic
Other
Painting pigments
External link
Pigments through the ages
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