瓷器专区Porcelain

1. Page introduction

Porcelain

Clay, fire and glaze, all three right, and the vessel holds

Porcelain is the most everyday of Chinese crafts: rice bowls, tea cups, vases, incense holders. Most homes have a few pieces. It is also the least explained. People see the color but not how the clay is worked, the wall thrown, the glaze mixed, the fire controlled.

This page covers only what is still made and still used: celadon from Longquan, white porcelain from Dehua, blue-and-white from Jingdezhen. Museum masterpieces and imperial ritual wares are out of scope; the space is kept for pieces you can hold.

2. Three places

Longquan celadon: Around Longquan in Zhejiang, porcelain stone, purple-gold clay, limestone and quartz are fired at high temperature in reduction. The glaze reads either powder blue or plum green; thick glazes are applied in three or four layers, each bisque-fired before the next. What is common today is tea ware, vases and tableware.

Dehua white: In Dehua, Fujian, kaolin is clean and low in iron, so the body fires fine and white and the wall can be thin enough to pass light. Large quantities went overseas by sea in the Ming dynasty, and Europeans called it blanc de chine. Today it is mostly tea ware, figures and tableware.

Jingdezhen blue-and-white: In Jingdezhen, Jiangxi, porcelain stone was combined with kaolin from the Yuan dynasty on. Cobalt is painted under the glaze, a clear glaze goes over it, and the piece is fired once at high temperature. What is common today is bowls, plates, dishes and tea sets.

3. The steps

Working the clay: Porcelain stone is crushed, washed, aged and wedged to take out air and coarse grains. Clay worked evenly is clay whose walls will not trap air when thrown.

Throwing and turning: Throwing happens on the wheel: the center is opened, the wall lifted, the form set. When the piece is half dry it goes onto the turning lathe, where the wall is trimmed to an even thickness and the foot ring rounded. A millimeter here shows after firing.

Glazing: Pouring, dipping, brushing and spraying are used on different parts. Thick glazes are applied, bisque-fired, applied again, several times over, so the layer ends up deep without running.

Setting and firing: The piece goes into a saggar and then the kiln. Celadon is fired around 1300°C in reduction; blue-and-white is fired once at high temperature. A small difference in temperature or atmosphere shifts the color.

4. What glaze and fire decide

Green: Celadon color is not painted on. It comes from iron in the glaze returning under reduction. The same recipe gives different depths at different points in the kiln, so one firing can produce several greens.

White: White porcelain depends on a clean body. The lower the iron, the truer the white; the thinner the wall, the softer the light that passes through.

Blue: Cobalt is painted on the raw body, the glaze goes over it, and the piece is fired once. The blue sits under the glaze and cannot wear off. The tone depends on the purity of the cobalt and the firing; in a good branch pattern the blue has depth.

5. Where it is used today

The table: Celadon rice bowls, white soup bowls and blue-and-white plates are what many households actually eat from. Glazed surfaces take no flavor and are easy to wash.

The tea table: Lidded bowls, small cups and fairness pitchers. White shows the color of the tea; celadon shows the light on the glaze.

Display: Vases, incense holders, lamp bases. Put one piece on a table with light coming from the side and the relation between glaze and form appears.

6. Where the fine work shows

Look at four places in a piece of everyday porcelain: whether the rim is thin and even and does not cut the lip; whether the foot ring is round and the piece sits without rocking; whether the glaze is even, with no pooling or bare patches; whether the blue-and-white pattern is clear and the blue has depth. A good piece does not need a close look. Put it on a table and let the light find it.