An inorganic color pigment used in printing inks. Ultramarine violet (chemical formula H2Na4:6Al6Si6O24S2) is a bright reddish violet with good lightfastness and heat resistance. It is used in inks produced for metal decorating, primarily to tone white enamels so as to prevent yellowing. (See Inorganic Color Pigments.)
('CI Pigment Violet 15 No. 77007'.)