Dyes and Pigments

Every manufactured object is colored by a dye or pigment. There are about 7,000 dyes and pigments, and new ones are patented every year. Dyes are used extensively in the textile industry and paper industry. Leather and wood are colored with dyes. Food is often colored with natural dyes or with a synthetic dye approved by a federal agency. Petroleum-based products such as waxes, lubricating oils, polishes, and gasoline are colored with dyes. Plastics, resins, and rubbers are usually colored by pigments. Dyes are used to stain biological samples, fur, and hair. Special dyes are added to photographic emulsions for color photographs.