Preventing Castings From Warping

The best way to evenly dry tiles (pressed tiles too) and slip castings, I have found, is to let them dry from the moment they drop out of the mold on wire racks such as these. If the clay is the same thickness throughout the piece, they will not warp or crack due to uneven shrinkage, so you can let them dry in the open air. The only problem, however, is that the edges of the castings tend to slip over the wires and fall through, creating at the very least a texture from the wire digging into the soft clay and at the very worst, a serious warping issue.

I fixed this problem by cutting window screening (found at any home improvement store) to fit the shelf and laying that over the top. This way, when the castings fall onto the shelf, the edges are supported by the screen and there is no warping.