A dye is a colored substance that chemically bonds to the substrate to which it is being applied. This distinguishes dyes from pigments which do not chemically bind to the material they color. Dye is generally applied in an aqueous solution and may require a mordant to improve the fastness of the dye on the fiber.
Drying colored cloth
Dyeing wool cloth, 1482: from a French translation of Bartolomaeus Anglicus
Historical collection of over 10,000 dyes at Technical University Dresden, Germany
RIT brand dye from mid-20th century Mexico, part of the permanent collection of the Museo del Objeto del Objeto
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. Dyes are often organic compounds whereas pigments are often inorganic. Pigments of prehistoric and historic value include ochre, charcoal, and lapis lazuli.
Pigments for sale at a market stall in Goa, India
The Milkmaid by Johannes Vermeer (c. 1658). Vermeer was lavish in his choice of expensive pigments, including lead-tin yellow, natural ultramarine, and madder lake, as shown in the vibrant painting.
Titian used the historic pigment vermilion to create the reds in the oil painting of Assunta, completed c. 1518.
Miracle of the Slave by Tintoretto (c. 1548). The son of a master dyer, Tintoretto used Carmine Red Lake pigment, derived from the cochineal insect, to achieve dramatic color effects.