Pigment yellow 12 for plastics P.Y.12 as a colorant for polymers. Although a certain tendency to migrate precludes its use in plasticized PVC, rigid PVC somewhat enhances its performance. Transparent varieties become sufficiently fast to light to equal step 6 on the Blue Scale; opaque types afford values between 2 and 5, depending on the pigment concentration and amount of TiO2 or depth of shade.  Good heat resistance also qualifies P.Y.12 for use in polyurethane foam; aromatic polyurethanes themselves are not very fast to light.