These Stainless Steel forms are ideal for casting and combing glass. They may be used in any size kiln. Glass may be fused thicker in this containment form. To use these forms, cut four 1/8 in thick fiber paper strips to line the walls of the form. This will keep the glass from sticking to the metal. Shelf primer is not recommended. Re-line the form before each use. 12 X 12 X 3/4" H O.D.(outside dimension). Free shipping.