Disperse Red 9, or 1-(methylamino)anthraquinone, is a red dye derived from anthraquinone. Disperse Red 9 is used in some older red and violet-red colored smoke formulations. It is used in the M18 colored smoke grenade and also often in dye packs. Its smoke-producing properties can be improved by coating the dye particles with an inert material, e.g. an epoxy resin.[1]