Krylon paints have introduced a new spray paint called "Fusion" made specifically for painting plastics. They indicate that this new paint is made specifically for painting polypropylene, polyethylene, ABS, and other types of plastics. I just finished painting a polypropylene canopy for an electric helicopter and this stuff does the trick. I wiped down the canopy with surface prep and sprayed the aerosol paint directly on the plastic with no primer as indicated on the directions. It was dry to the touch in about 15 minutes and per the directions I let it cure for 7 days. I got a real nice gloss finish that is VERY durable. It is not however fuel proof. I have some left over plastic and am going to paint it with the "Fusion", let it cure for the 7 day period and see if I can top coat it with crystal clear Lustercoat to see if it is compatible.