Types of Paint for Styrofoam
Styrofoam is a trademarked brand of expanded polystyrene foam (a synthetic resin). While it is used primarily as packaging material—because of its soft, compressible nature—Styrofoam is also commonly used in arts and crafts projects, especially in the form of balls. However, according to thriftyfun.com (see Reference 1), you can't use just any old paint to decorate Styrofoam, as paint can actually eat away the material and ruin your project. Some of the best types of paint for Styrofoam include acrylic craft paint and Styrofoam-safe spray paint.
Acrylic Craft Paint
According to craft.dow.com (see Reference 2), acrylic craft paint is one of the best when it comes to painting directly on Styrofoam. You can find this type of paint—which is used for all types of projects—at any arts and crafts store. However, because of the rough, cratered surface of Styrofoam, you will have to scrub or rub the paint extensively to ensure you fill all the crevices. Craft.dow.com recommends painting at least two coats to ensure optimal coverage. Another technique is to pour acrylic craft paint into a resealable plastic bag, then put your Styrofoam inside. Rotate and move the bag around the Styrofoam to ensure that the paint is absorbed equally on all sides.
Styrofoam-Safe Spray Paint
You should never use traditional spray paint on Styrofoam, as—according to thriftyfun.com—it will deteriorate the material, ruining your project and creating a terrible mess. Instead, stick to spray paint products specifically labeled as safe for Styrofoam. Some of these include model spray paints, most notably the variety produced by Testors, which are typically made from acrylic, latex, or a combination of both. Other options include water-based spray paints (such as those made by Krylon) and floral spray paints, which are used primarily for coloring floral arrangements. No matter what type of spray paint you use, you should test it out on a sample piece of Styrofoam before you begin your project.
Other Painting Options
Instead of worrying about the effects a particular paint will have on Styrofoam’s delicate surface, cover your entire block, ball, or other Styrofoam piece in a protective coating. Some of the best options for this include Plaster of Paris, papier-mâché, and foam sealants, such as Foam Finish. You might have to apply multiple coats and smooth the coating with sandpaper once dry. You will then be able to use any type of paint (including traditional spray paint) on your Styrofoam craft, without having to worry about deterioration.
- styrofoam business image by robert mobley from Fotolia.com