We'll send you a sheet of blank magnetic material that is brownish black on both sides. This is the same strong but flexible material used for bumper magnets. Material is .020" thick. Material can be trimmed with a pair of scissors, or better yet, a paper cutter. Great for other crafts. Also available in several other sizes. We also offer a slightly thicker magnetic material for heavier duty applications. Search our store using the Lifeweaver_llc link above.