Pigment

Pigments for sale at a market stall in Goa, India

A pigment is a powder used to add color or change visual appearance. Pigments are completely or nearly insoluble and chemically unreactive in water or another medium; in contrast, dyes are colored substances which are soluble or go into solution at some stage in their use.[1][2] Dyes are often organic compounds whereas pigments are often inorganic. Pigments of prehistoric and historic value include ochre, charcoal, and lapis lazuli.

  1. ^ Gürses, A.; Açıkyıldız, M.; Güneş, K.; Gürses, M.S. (2016). "Dyes and Pigments: Their Structure and Properties". Dyes and Pigments. Springer. pp. 13–29. doi:10.1007/978-3-319-33892-7_2. Dyes are colored substances which are soluble or go into solution during the application process and impart color by selective absorption of light. Pigments are colored, colorless, or fluorescent particulate organic or inorganic finely divided solids which are usually insoluble in, and essentially chemically unaffected by, the vehicle or medium in which they are incorporated.
  2. ^ Völz, Hans G.; et al. "Pigments, Inorganic". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a20_243.pub2. ISBN 3527306730.