Dyestuffs are used in the surface coating and printing industries, where a very high level of transparency is required, for the production of colored metal foils and films, flamboyant finishes in the paint industry and for wood stains, among others. Due to advances in resin technology, dyes are now also being used in specific automotive finishes because of their color and transparency properties. The dyestuffs for those applications are soluble in various solvents. Basic dyestuffs are used by printing ink industry with lacking agents such as tannic acid. These chemicals are used exclusively in the coloring of textiles, inks, food products, and other substances. Dyestuffs must be capable of entering and coloring textile fibers or other substances. Chemical radicals, known as auxochromes, have the property of anchoring the desired dye effectively.