Porcelain is an integral thread of the fabric of Chinese culture. In the 14th century, while Europeans were still eating from low-fired earthenware or wooden dishes, the Chinese had developed the first underglazed porcelain. They were using cobalt, originally imported from Iran during the Yuan period (1279 to 1368 A.D.), to add exceptional shades of color, from pale blue to nearly black, to translucent white wares. As soon as Marco Polo brought back a few samples, the world couldnt and still cant get enough of it.

Copper is the other basic color of underglaze decoration. It delivers hues that range from the first muddy brown of the early Ming dynasty to the true red of the 18th century. "Peach bloom or unripened peach is a greenish tinge produced when copper has oxidized.

Overglaze decoration was done in various kinds of enamels and called famille rose (a French expression meaning "pink family"). There is famille verte (green), famille noire (black), and famille jaune (yellow). Pieces with a black background enameled in famille rose or in combinations such as rose-verte (pink and green) was a late-17th-century innovation. It is generally agreed that overglaze enamel decoration reached its height in the 18th century.

The Japanese at this time were also developing porcelain, mostly in the form of ceremonial objects like the tea ceremony. The famous Satsuma porcelain you hear so much about was a 17th-century innovation, adopted from Korea and then greatly improved upon. By the Meiji period (1868- 1912) the Japanese had taken enameling to a new level. High fired and reflecting the Japanese characteristics of meticulousness, precision and definition, these porcelain paintings were highly conceptual. The art of Japanese enameled porcelains peaked between 1880 and 1920, whereas Chinese porcelain was at its best between 1710 and 1810.

In the last few years, particularly beautiful and particularly rare porcelains have become inordinately valuable. In March 2008, we sold a large Hongwu vase during Asia Week in New York City for $1.2 million. Fortunately, there is still a tremendous amount of beauty to be found in within an affordable price range. Slight flaws will bring the price way down, and yet the items are still very collectible and consistently appreciate in value.

Generally speaking, flaws on the glaze occur most frequently during firing. While several overglaze colors can theoretically be fired at the same time, more often than not they are fired separately. If gilded, the gold was the last to go on. It is the first to wear off.

When evaluating a particular piece of porcelain, start by viewing it as though it were perfect and determine what price perfection. (Access our online catalogs and the prices realized for each auction to use as a reliable price guide.) From there, adjudicate the flaws in the piece and judge the value in its current condition.

My own opinion is that very fine porcelain pieces with some damage or restoration are great buys today. A Ch'ien Lung bowl, for instance, in perfect condition would be out of the reach of most people. But if you find one with a small chip that was expertly repaired and the bowl would make a beautiful addition to your collection, buy it. They arent making them like that anymore and the chances of it holding its value, even appreciating, is enormous.

As for copies, you can spot them fairly easily. The decoration is usually too carefully drawn. Since porcelain does not show a lot of wear, you will notice immediately if a piece looks like somebody has taken fine steel wool and scrubbed it, put it up on a buffing wheel or tried to tone it down with chemicals.

Japanese porcelain from the Meiji period and notably from the Kutani (nine rivers Nine Rivers?) region has never really been effectively reproduced; the repros that do exist are noticeably inferior. Also, few reproductions come out of Japan these days.