Create a large fused glass picture frame. Fill casting mold with frit, powder or sheet glass. This mold is a perfect way to use up the scrap glass you have in your studio. A 3/8" resided bottom allows you to place the photo behind a Plexiglass before gluing easel back on. Holds a 4" x 6" photograph, one of the most common sizes. Coat mold with casting primer before use.