About this term

Source: Oxford University Press

Finely powdered colouring matter that is suspended in a binding medium to form paint; for pastel (see Pastel, ยง1) the pigment is moulded into sticks with the aid of a binding medium. In most forms of painting the binding medium, which may be oil, egg yolk, water or a variety of other substances, holds the pigment particles together and attaches them to a surface. In Fresco painting, however, the pigments are mixed with water for application, but when dry they form an integral part of the surface of the plaster.

Karin Groen

From Grove Art Online