What do you have to do before putting clay in a kiln?

The clay must slowly, completely dried. If it is still wet inside of the wall of the pot or sculpture then the resulting steam may cause the piece to explode. One good way to tell if it is dry is to hold it to your face. If it feels cool (from the evaporation), then it is still wet. If you try to dry the piece too rapidly, you can create cracks do to the uneven shrinkage of the clay.