An organic color pigment used in printing inks. Permanent Red "R" is a bright orange red which possesses high lightfastness and acid and alkali resistance, but low heat resistance. It is inexpensive, and used in many different applications, but printability problems make it difficult to produce effective formulations. (See also Organic Color Pigments.)
Also produced as Chlorinated Para Red ('CI Pigment Red 4 No. 12085').