Two ingredients are needed for the actual construction; pottery clay and a tempering material. The clay occurs in a shale layer at the foot of the upper cliff of the canyon wall. There are many deposits, large and small, and each woman has a favorite place from which she obtains her clay. Up the canyon from Cliff Palace, at the head of the right-hand fork, is an excellent deposit that is favored by many of the women. The nights are now without freezing temperatures that would render the digging too difficult so the women begin to make pottery. Early in the morning the potter leaves Cliff Palace and sets out for her favorite clay bed. She carries a large basket and a digging stick and is accompanied by any of her daughters who are learning the art. The clay is usually soft and easy to dig and she soon returns with a basket of blue-gray earth. The clay is spread out in the sun to dry and all stones and foreign particles are picked out. After drying thoroughly it is ground very fine on a metate, the same flat stone on which corn is ground. It is now ready for use. The tempering material comes from an odd source. The woman simply goes out on the trash pile below the cave and picks up a quantity of broken pottery. This she grinds up just as she did the clay until it looks like fine sand. This tempering material is very important for it keeps the vessels from shrinking and cracking as they dry. Many centuries ago the ancestors of these women used sand and grit for temper. Some still use them but most of the women use ground-up potsherds. They are just as good and are much easier to obtain. Year after year the broken pots have been ground up and used again. Some of the particles the women are using today may have been used by their ancestors centuries ago. When the clay and the temper are ready they are mixed, about one part of temper being used to two parts of clay. With her fingers the potter mixes the dry materials very thoroughly for a poor mix will give the pottery an uneven quality. Finally she is satisfied and water is added until she has a thick, heavy paste that does not stick to her hands as she works it. After this paste has been very thoroughly kneaded, actual construction of the pot begins.