Quick Tip: How to Prevent Warping in Large Platters Toni McPhee

Learning how to make a platter is an important skill for a potter. But platters can be a source of frustration when they warp or crack during the drying or firing processes. If you don't take steps to prevent warping or cracking, you might be heartbroken when your platter comes out of the kiln.

Toni McPhee came up with a great solution to this problem: a cement board bat. The cement board slowly pulls moisture out of the entire platter, which helps dry the platter evenly. In this Quick Tip, she shares how to easily make and use these bats! Genius! –Jennifer Poellot Harnetty, editor

I throw a lot of flat-based platters for my customers. The middle of platters tend to warp upward in the middle as they dry, requiring a lot of care in draping and a very slow drying process. To speed the process and guarantee that the platters dry flat, I cut 16-inch round bats from thick, smooth-sided cement boards.

The cement board is so absorbent that it pulls the clay downward onto the smooth surface as it dries, eliminating almost all warping problems during the firing. I tuck the platter and cement board into a rubbermaid cupboard for about 4–6 hours and it is ready for a signature and final carving of the design.