Pigment Yellow 81 This pigment affords a very greenish yellow. Its hue is similar to that of the monoazo yellow pigment P.Y.3, but white reductions are much stronger exhibiting considerably improved solvent and migration resistance. Although P.Y.81 shows satisfactory lightfastness, it is not quite as lightfast as P.Y.3. P.Y.81 is recognized throughout the paint industry for its fastness to overcoating and very good solvent fastness in industrial application. Most types exhibit good hiding power. In plastics application, P.Y.81 is very resistant to bleeding, provided the appropriate concentration limits are observed. Its heat resistance makes it a useful colorant for polyolefins. P.Y.81 was said to be heat stable up to 260°C for 5 minutes, depending on the depth of shade. The pigment was thus much more heat resistant than other diarylide yellow pigments