The art of ceramics is one of the oldest known, dating to prehistoric times. Clay is a special kind of earth, found all over the world that is easily worked when moist, but can be hardened and made waterproof by exposure to heat. The earliest forms of construction were pinched -- that is, the clay is formed with the fingers to the desired shape.

Coiled forms were built up from long rolls of clay, and then smoothed with the fingers or a smooth piece of wood or stone.This link will show you how coiled construction is done .

Slab construction involves rolling out a flat sheet of clay, cutting shapes from the sheet, and assembling them into the desired forms. All of these ancient methods are still practiced by craftspersons around the world. This link will show you how slab construction is done .

Wheel throwing to make clay objects was developed in China at least as early as 3500 BC. This involves centering a ball of clay on a table that is turned by kicking a weighted wheel, or operating a treadle. The form is shaped by the potters hands, but is perfectly symmetrical, because of the turning of the wheel as he shapes the clay. The potters wheel and the wood lathe in fact operate on the same principal. Throwing is the method most commonly used today for handmade ceramics. This link shows the wheel throwing process .

The earliest clay objects were earthenware-- that is, hardened in an open fire. This "low fire" method results in a porous, relatively soft material, which is not waterproof.

The next stage of development was the invention of the kiln-- a type of oven in which temperatures much higher than an open fire can be obtained. This "high fire" method produces a type of ceramic known as stoneware, which is also opaque, but much harder and stronger than earthenware, and also waterproof, even when unglazed.

Porcelain is considered to be the finest quality of ceramics. It is translucent, self glazing, white, and very hard. Porcelain was developed in China, and is made of a special type of clay called kaolin, plus feldspar. The secret of porcelain was not discovered in Europe until the early 18th century, when the first porcelain factory was established at Meissen, in Saxony (now Germany).

In mass production of ceramics, slip casting, is commonly used. Clay is reduced to a liquid, or slip, by the addition of water. the slip is then poured into a mold. Jolleying is a mechanical method of turning a ball of clay, using a mechanical device to force the clay into a mold while being turned.

The Surface decoration of ceramics began with simply burnishing or polishing the surface of the raw clay with a smooth tool. The surface could also be carved or incised to create decorative patterns or images. Later, designs were painted on the surface, using clay-like pigments known as slip that could be fired onto the surface for permanence. By the 14th century, glazes came into use. Glazes were glass-like mixtures of minerals and silica that produced a glossy, hard finish when fired. Glazes come in many colors, and could be applied by dipping or painting to achieve a variety of decorative effects. Some of the brightest colors used in the past came from materials now known to be harmful: lead glazes were particularly common in colorful painted folk pottery, notably from Mexico and Italy; uranium was also used to produce a vivid orange glaze on tableware until the 1950's. Article with such glazes should not be used for eating on a regular basis.

The modern handcrafted ceramics movement in the United States and England dates back to the 1930's and 40's. Bernard Leach was a leading figure in the development of this modern style, which owes a great deal to the folk ceramic traditions of Japan and China.

This web site Copyright © 1995 by Charlotte Jirousek
Questions or comments? Let us know at caj7@cornell.edu.