Painting Plastics
Plastics are perhaps the most difficult surfaces to paint. Their chemical composition and smooth surface do not promote good paint adhesion, and the fact that plastics can expand and contract at a greater rate than many paints leaves them vulnerable to flaking paint, even when you think you have the coating securely adhered.
With proper preparation and specialty products, however, you can paint plastics and not have to worry about the durability of the finish.
For interior walls (tiled with plastic tile, for example, or finished with other plastic products), apply a high-adhesion latex stain-blocking primer. For bathroom and kitchen walls not subject to constant exposure to water, use a top-of-the line-interior latex paint. Shower walls and similar surfaces do not make suitable candidates for paint.
For extra insurance against peeling and cracking, ask your paint dealer about primers and paints made specifically for plastic surfaces. They will give you a great deal of versatility in transforming drab outdoor objects into attractive ornaments.