An organic color pigment used in printing inks. Indanthrene Blue is a reddish transparent blue pigment possessing high lightfastness and resistance to heat, acids, alkalis, solvents, and soaps. It is well-suited for use in all types of inks, but its expense limits its use to applications whose chemical resistance requirements make the expense warranted, such as in the gravure printing of soap wrappers and packaging. (See also Organic Color Pigments.)
Also known as Anthraquinonoid Blue ('CI Pigment Blue 60 No. 69800', while a chlorinated version is a redder shade and is categorized as CI Pigment Blue 64').