Floquil Railroad Polly Scale Acrylic Paint Grimy Black (1 Ounce) Certified non-toxic, convenient water wash-up High performance brushing and excellent airbrushing characteristics Thins with water and is completely waterproof when dry For airbrushing, thin with Testors Thinner 50496. Thin paint 75% paint to 25% thinner. Adjust compressor to 16-18 PSI. For Aztek use high flow nozzles, Red #9342C, Orange #9343C, or Yellow #9344C. Other brand airbrushes use a #3 needle.