Back to School Gallery Alphabet Puzzle Fun to make and use. Pin two thin (1/2"-1") sheets of 16"x12" foam together. Trim the edges so they match well and round out the corners. Sand if neccesary.Print out the alphabet from your computer. Bold wide letters with lots of curves are easiest. Blow up to 14"x10" on a copy machine. Trace the letters onto the top piece of foam.Separate the two pieces of foam. Cut out the letters you traced on the top piece. Sand the edges of the letters and the cutouts that they will fit back into. Glue the two sheets of foam together.Paint the letters different colors, and paint the sheets a blackboard green. Hot Tip: Cut squiggly lines between the letters instead of going straight across to the next letter. This makes the cuts between the letters less noticeable. You can even fill the lines with Hot Wire Foam Coat, or white paintable caulking.