THERE ARE THREEkinds of pottery, all of which started life as clay: Stoneware is a mixture of clays fired at very high temperatures (about 2,400 degrees); earthenware, also from a mix of clays, is often glazed with bright colors and fired at comparatively low temperatures (less than 2,000 degrees), and china, usually of one kind of clay fired at low temperatures. It is the purest and most delicate form of pottery, so fine that one can see a hand held under it.
Pottery is an ancient craft, first worked at about 7000 BC in Egypt. The Egyptians started glazing their wares about 3000 BC, and by 1600 BC the Cretans had refined the art to include curved figures and depictions of animals. About 1500 BC, the Chinese were using the pottery wheel to make more precisely shaped items.
Today the term pottery is used to describe the function of the finished piece rather than the characteristics of the raw material. Pottery refers to useful items--cups, vases, plates--and includes stoneware and earthenware. Ceramics is used to describe more decorative pieces, such as animals, figures--and also vases. In all cases and regardless of name, the shaped clay can (and in some cases should) be glazed before being fired in a large oven, or kiln, a process that sets the shape and finish. (Terra cotta, a kind of earthenware, is fired but not glazed.) Glazing adds subtle color (or no color), but, more important, it adds a finish that seals the clay when fired at hot-enough temperatures and makes the object water- and oven-proof. Ceramic items can be painted as well as glazed.
Four basic techniques are used to transform a lump of clay: coil, slab, mold and wheel. For the first, a piece of clay is rolled into a long rope and then shaped by coiling the rope around and up. A slab of clay is rolled flat, then cut into pieces and put together in various shapes, a system best suited for platters and straight-sided items. Pinch pots--literally pinched into shape with thumb and fingers--are a variation of the slab process. Molds allow a greater variety of finished product and require less skill in the initial stages, because the clay is shaped by the container into which it is poured, not by the potter; this is where the figures are born. The wheel, for many the symbol of pottery, is a revolving platform that holds the clay while the potter shapes it with his or her hands. It is perhaps the simplest merger of earth, human and technology, and the result can be more than the sum of its parts.
Classes in pottery making are available at Potters Studio in West Los Angeles, Ceramic Factory in Santa Ana, Gary's Pottery in Manhattan Beach, Cahuenga Potters in North Hollywood, and many other locations in Southern California--check under the Ceramic Instruction heading in the Yellow Pages.
Two publications dealing with pottery making are American Ceramics, 15 W. 44th St., New York, N.Y. 10036, $24 for 12 issues, and Ceramics Monthly, P.O. Box 12448, Columbus, Ohio 43212-9988, $18 for nine issues.