Things You'll Need
Styrofoam balls are frequently used for craft projects, including science, holiday, preschool and home decorating crafts. Spray painting a Styrofoam ball is tricky, however, as a Styrofoam ball that is directly spray painted can melt under a heavy coating of certain paints. You must take precautions to paint the ball safely.
Cover a Styrofoam ball in aluminum foil or fabric. Wrap aluminum foil around the ball in a single layer. It may take some work to get the surface flat, and fabric may make for a more rounded look if you need the Styrofoam to look smooth. If using fabric, wrap in a single layer and place push pins in the places the fabric does not lay down or is overlapping and creating a raised area. You won't need push pins for aluminum foil.
Stick a wooden skewer in the Styrofoam ball. Use skewers with a pointed end that will go through the fabric or aluminum foil.
Hold the Styrofoam ball up by the wooden skewer and begin spraying with spray paint. Hold the can at least 8 inches away to avoid pools of paint and dripping. The first layer may not cover the entire ball completely.
Allow the ball to dry. Set it upright by placing the skewer in a foam block or other holder to keep it stationary while drying.
Apply another layer of paint as in Step 3. Allow to dry and then continue with craft project as planned.
Use fabric scraps, the thinner the better, to wrap the Styrofoam ball. The fabric will not show after it is spray painted. Styrofoam balls can be painted without covering by using acrylic paint and a paintbrush. This difference is a smoother surface, but it takes more time.