Medium Rectangular Serving Platter - Fusible Glass Slumping Molds Mold measures approx. 13.25" L x 6" W x 1" H. To use, simply pretreat the mold with kiln wash or nitride spray, and slump your prefused or sheet glass (cut to size) using the included slumping kiln schedule. For best results, always elevate this mold off the kiln shelf by at least 1" before firing. Comes with complete New Hampshire Craftworks Mold Care and Firing Schedule.