A type of organic color pigment used in printing inks, also called azo yellows or arylide yellows. Hansa yellows are strong, opaque pigments (about three to five times stronger than chrome yellows), are fast-to-light, and possess a high degree of resistance to chemicals. They vary from a greenish yellow to a bright, warm yellow (see color index reference chart below), and are often used to enhance the color of chrome yellows. They are used in both paste and liquid inks, and work well in letterpress and lithographic processes, and are especially used on soap packages. Their color strength is less than that of diarylide yellows, and have been replaced by diarylides in many cases.
The term Hansa is a trade name, and these dyes are more properly known as aceto-acetarylamides. (See also Organic Color Pigments.)
('CI Pigment Yellow 1, 3, 4, 65, 73, 74, 97, 98'.)