There are three main kinds of porcelain: (1) hard-paste porcelain, (2) soft-paste porcelain, and (3) bone china. The differences between these types of porcelain are based on the material from which they are made. This material is called the body or paste.

1. Hard Paste Porcelain

Hard-paste porcelain, which is sometimes called true porcelain or natural porcelain, has always been the model and ideal of porcelain makers. It is the type of porcelain first developed by the Chinese from kaolin and petuntse. Hard-paste porcelain resists melting far better than other kinds of porcelain. For this reason, it can be fired at higher temperatures. These hot temperatures cause the body and the glaze to become one. When hard-paste porcelain is broken, it is impossible to distinguish the body from the glaze.

The proportions of kaolin and petuntse in hard-paste porcelain may vary. The porcelain is said to be severe if the percentage of kaolin is high, and mild if the percentage of kaolin is low. Most collectors of porcelain prefer mild porcelain because of its mellow, satiny appearance. In comparison, severe porcelain may seem harsh and cold.

2. Soft Paste Porcelain

Soft-paste porcelain, sometimes called artificial porcelain, was developed in Europe in an attempt to imitate Chinese hard-paste porcelain. Experimenters used a wide variety of materials in their efforts to produce a substance that was hard, white, and translucent. They eventually developed soft-paste porcelain by using mixtures of fine clay and glasslike substances. These materials melt at the high temperatures used in making hard-paste porcelain. For this reason, soft-paste porcelain is fired at lower temperatures and does not completely vitrify--that is, it remains somewhat porous. Breaking a piece of soft-paste porcelain reveals a grainy body covered with a glassy layer of glaze.

Although soft-paste porcelain was invented in imitation of true porcelain, it has merits of its own. Most of it is creamy in tone, and some people prefer this color to pure white. In addition, the colors used to decorate it merge with the glaze to produce a soft, silky effect that appeals to many collectors.

3. Bone China

Bone china is basically made by adding bone ash (burned animal bones) to kaolin and petuntse. English porcelain makers discovered this combination of ingredients about 1750, and England still produces nearly all the world's bone china. Though not as hard as true porcelain, bone china is more durable than soft-paste porcelain. The bone ash greatly increases the translucence of the porcelain.

Decorating porcelain

A piece of porcelain is shaped on a potter's wheel or in a mold. After this stage, the porcelain worker may decorate it by (1) surface modifications, (2) painting, or (3) transfer printing.

Surface modifications are achieved by incising (carving), perforating (poking holes), and embossing (applying raised designs). A well-known method of embossing porcelain is to apply a mixture of water and clay, called slip, to the item with a brush. Relief designs (three-dimensional effects) are usually molded separately and then attached to the porcelain.

Painting the porcelain surface may be done in several ways. One method is to use a colored glaze, such as the famous Chinese celadon. This glaze is a soft gray-green color. Another type of decoration is underglaze (designs painted on a piece before it is glazed). A deep blue made from the metal cobalt is the most dependable color used for underglazing. Cobalt blue has been widely used both in China and in Europe.

Paints that are applied over the glaze are commonly called enamels. A large variety of enamel colors were perfected at an early period. Most of them are made from metallic oxides, such as iron, copper, and manganese. Enamel colors require a second firing to make them permanent.

Porcelain painting in Europe differed greatly from porcelain painting in China. Chinese decorators separated each color from the next with a dark outline, but European artists blended colors together with no separating line. In addition, Europeans used decorations purely for their artistic value, but Chinese decorations were symbolic. For example, a pomegranate design symbolized a wish for many offspring because a pomegranate has many seeds.

Transfer printing revolutionized the porcelain industry in 1756 by enabling workers to decorate wares much faster than they could by hand. In this process, a design is engraved on a copper plate, inked with ceramic color, and transferred to tissue paper. While the color is still wet, the tissue paper is pressed against a porcelain object, leaving the design on its surface.

History of porcelain

Oriental porcelain

The Chinese probably made the first true porcelain during the Tang dynasty (618-907). The techniques for combining the proper ingredients and firing the mixture at extremely high temperatures gradually developed out of the manufacture of stoneware. During the Song dynasty (960-1279), Chinese emperors started royal factories to produce porcelain for their palaces. Since the 1300's, most Chinese porcelain has been made in the city of Jingdezhen.

For centuries, the Chinese made the world's finest porcelain. Collectors regard many porcelain bowls and vases produced during the Ming dynasty (1368-1644) and Qing dynasty (1644-1912) as artistic treasures. Porcelain makers perfected a famous blue and white underglazed procelain during the Ming period. Painting over the glaze with enamel colors also became a common decorating technique at this time. During the Qing period, the Chinese developed a great variety of patterns and colors and exported porcelain objects to Europe in increasing numbers.

By the 1100's, the secret of making porcelain had spread to Korea and to Japan in the 1500's. Workers in these countries also created beautiful porcelain objects. A Japanese porcelain called Kakiemon was first produced during the 1600's. It features simple designs on a white background. Another well-known Japanese porcelain called Imari ware, or Arita, is famous for its dense decorations in deep blue and red.

European porcelain

As early as the 1100's, traders brought Chinese porcelain to Europe, where it became greatly admired. However, it was so rare and expensive that only wealthy people could afford it.

As trade with the Orient grew during the 1600's, porcelain became popular with the general public. The custom of drinking tea, coffee, and chocolate became widespread and created a huge demand for porcelain cups and saucers. European manufacturers responded by trying to make hard-paste porcelain themselves, but for a long time they failed to discover the secret. Nevertheless, some of their experiments resulted in beautiful soft-paste porcelain. The first European soft-paste porcelain was produced in Florence, Italy, about 1575.

By the 1700's, porcelain manufactured in many parts of Europe was starting to compete with Chinese porcelain. France, Germany, Italy, and England became the major centers for European porcelain production.

French porcelain

France became famous during the 1700's as the leading producer of soft-paste porcelain. The first factories were established at Rouen, St. Cloud, Lille, and Chantilly.

The most celebrated type of soft-paste porcelain was first produced at Vincennes in 1738. In 1756, the factory was moved to the town of Sevres. Its soft-paste porcelain became known as Sevres. The earliest Sevres had graceful shapes and soft colors. Sevres pieces produced from 1750 to 1770 were decorated with brilliant colors and heavy gilding. Many of these pieces had richly colored backgrounds and white panels painted with birds, flowers, landscapes, or people. Sevres is also noted for its fine figurines of biscuit (unglazed porcelain).

Beginning in 1771, a hard-paste porcelain industry developed near Limoges, where kaolin deposits had been discovered. By the 1800's, Limoges had become one of the largest porcelain centers in Europe. An American named David Haviland opened a porcelain factory at Limoges in 1842 to make tableware for the American market. Haviland porcelain features soft colors that blend together and small floral patterns.

German porcelain

A German chemist named Johann Friedrich Bottger discovered the secret of making hard-paste porcelain in 1708 or 1709. This discovery led to the establishment of a porcelain factory in Meissen in 1710. Meissen porcelain is sometimes called Dresden because Bottger first worked near the city. For nearly a century, it surpassed in quality all other hard-paste porcelain made in Europe.

The great success of Meissen porcelain can be partly attributed to the fine artists who decorated it. They painted the wares with an amazing variety of colors and designs. Johann Horoldt (or Herold), who became chief painter in 1720, produced beautiful Chinese and Japanese as well as European designs. Johann Kandler, who worked from about 1730 to 1770, is famous for his exquisite figures of animals and people.

Political disorder in Germany and competition from Sevres porcelain drove the Meissen factory into decline during the late 1700's. It continued to operate but did not make wares of the same artistic quality.

English porcelain

England is well known as the center for the production of bone china. Before the invention of bone china, the English manufactured fine soft-paste porcelain at Chelsea, Bow, and Derby. Most of this English porcelain was styled after Oriental and Continental designs.

Worcester porcelain, first produced in 1751, is one of the oldest and best English porcelains. During its early years, the Worcester factory produced soft-paste porcelain, much of it decorated with Chinese designs in blue underglaze. Since the 1760's, it has manufactured bone china in a wide variety of colors and patterns.

Josiah Spode developed a bone china paste that became the standard English paste in 1800. Spode china featured a large number of designs but was especially noted for its exotic birds.

Most of the famous English Wedgwood ware is not porcelain at all, but earthenware or stoneware. Nevertheless, its classical Greek figures and reliefs became enormously popular and had a great influence on porcelain designs throughout Europe.

Modern porcelain

Technical advances enabled the porcelain industry to produce porcelain in large quantities. Today, extensive porcelain making is carried out in the United States, Europe, and Japan. Some notable examples of fine contemporary porcelain are American Lenox, German Rosenthal, and Japanese Noritake.

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Contributor: William C. Gates, Jr., M.A., Curator and Historian, Ohio Historical Society.

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