Dewatering: clay is made from earth, the earth is made up of water and clay and dewatering is to separate one from the other. It can be laid out in the sun, left on top of an absorbent surface such as brick or wood or passed through a cloth bag. Put the clay on to a piece of square material, which has a large weave to let the water run out, pull up the four corners, tie them together and hang it up over a bucket. In the past, large brick outdoor sieves were used so the water could run back into the ground. A potter tossed and turned it until it had the right density, then sieved and made it into plastic clay. This is now done by manufacturers and most potters buy prepared clay.