Things You'll Need
Soap and water
Sandpaper (400-600 grit)
Plastic adhesion primer
Spray paint for plastic
Shiny, smooth plastic surfaces resist paint. If you attempt to paint unprepared plastic, the paint will bead up and roll off the surface. You can paint over plastic if you prepare the surface properly, however. Then you can paint plastic balls to use as Christmas ornaments or as part of a homemade game. Look for the necessary supplies at a craft or hardware store.
Wash the plastic ball thoroughly. Use soap and water to remove dirt, dust and grit from the plastic surface, and then let the ball dry completely.
Sand the plastic surface using sandpaper with a grit number of 400-600. Thoroughly sand the entire surface; paint will not stick to any parts of the ball that are left shiny and smooth.
Wash the ball again to remove any grit that has accumulated during sanding. Let it dry.
Apply one or two coats of plastic adhesion primer. Look for Plastic Adhesion Promoter by SEM. This product usually comes in a spray can. Follow any directions that come with the product. Ensure that your work area is well ventilated before you apply the primer. Let the primer dry.
Apply spray paint designed specifically for plastic, such as Krylon Fusion Spray Paint for Plastic. Apply multiple coats for better results, letting each coat dry before applying the next. Follow the directions on the paint can to determine how many coats are best.
Suspend the ball on a small stand to keep it still while you apply paint coats. You can return to the area that was covered by the stand once the other paint coats have dried.
Wear gloves when applying primer and spray paint.