Made of vermiculite. 7 in (17.7cm) square, 5.25 in (13.3 cm) round opening.
Pre-fire and line with fiber paper before using with glass. For more information about vermiculite products, including pre-firing instructions, see Tips for Using Vermiculite Board.
Also please be sure to check out our Quick Tip: Kilncast and Slumped Bowl for a great project idea employing this mold.