ABS plastic is used in many household, plumbing and construction projects. It can take the form of a water pipe or a chair, for instance. If you have ABS material that will be outdoors and exposed to sunlight, it is best to paint the plastic since untreated plastic will be destroyed by the sun's UV rays. Preparing ABS to be painted is easy, and you can use just about any solvent-based paint, but two brands known for their quality paint for ABS materials are Rustoleum and Hercules.
Place a small amount of mild liquid dish soap on a dry sponge and clean the ABS object you want to paint. When the surface is completely soaped up, rinse it with clean water and use paper towels to dry the surface. Set your ABS object aside for half an hour to allow for it to completely air-dry.
Rub the surface of the object with a fine-grade sandpaper; you do not want to scratch the surface but gently abrade it. The surface should no longer feel "glass-smooth" when you are done. ABS requires no primer paint, but the surface must be abraded before the paint is applied.
Apply the solvent-based paint with your paintbrush to the ABS in thin layers. Allow each layer to dry completely according to the instructions on your brand of paint before applying the next layer.
Use spray paint to cover large, flat surfaces of ABS evenly.
Always test the paint on a small area of the ABS before completely covering the object. Watch to see if the paint reacts in any way with the plastic; if it does not, continue painting. Even if your paint is specifically designed for ABS, impurities in the ABS itself can cause a reaction. If the paint and plastic do react to each other (the plastic may disintegrate, or the paint might streak and refuse to stick), clean the wet paint off the ABS and try a different kind of paint.