Dyestuffs
Dyestuffs, any of a large group of chemicals almost exclusively organic in nature, used for the coloring of textiles, inks, food products, and other substances. Modern industrial terminology defines a dyestuff as a product containing pure organic dye and cutting agents or fillers that make the product easier to handle. Dyes are not to be confused with pigments, which are pulverized colored substances that must be mixed with adhesive binding agents before being applied to surfaces. See Dyeing . The color properties of organic compounds depend on their structure. In general, the colored compounds used as dyes are unsaturated organic chemicals. The quality of possessing color is particularly noticeable in compounds containing certain well-defined chemically unsaturated groupings. These groups, known as chromophores (color bearers), are not all equally effective in producing color. Dyestuffs must be capable of entering and coloring textile fibers or other substances. Chemical radicals, kno