The Ch'engni inkstone (¡q¼áªdµx) is considered the best of all the ceramic types. Gaining popularity during the T'ang Dynasty (618-907), it was by far the most difficult of all inkstones, ceramic or otherwise, to manufacture. According to historical records, first a cloth bag was suspended in a running stream. After approximately one year, the bag was removed from the water, by which time fme silt had gathered in the bag. Small rocks and other impurities were then filtered out, and the remaining silt dried in the sun. It was next mixed with huang tan t'uan ( ¶À¤¦¹Î), a resinous plant substance, and kneaded together. After being shaped in a mold and decorated with a knife, it was removed from the mold, placed in a bag containing rice husks and cow manure, and hung in a dark, cool place to dry. It was later fired in a ceramic kiln for approximately ten days. After cooling, it was covered with black wax, submerged in a vat of rice vinegar, and finally steamed over high heat about a half dozen times.

The color of the finished inkstone depended on the area of production and other variables such as the temperature of the kiln. If the last couple of production steps sound like a page from the Chinese culinary arts, then the names given to the different colors of inkstones are off the menu of a seafood restaurant. These include, among others, "shrimp head red," "crab shell blue," "eel orange," and ''fish stomach white." The final appearance of the Ch'engni inkstone was very similar to that of stone, and supposedly equally as hard. It had a metallic sound to it when struck, and even a steel knife could not scratch its surface. Although these inkstones were highly regarded at the time, difficulty of production was no doubt partially responsible for their growing scarcity after the T'ang Dynasty.

By the Sung Dynasty (960-1279), inkstones once more started to be made almost exclusively of stone. This reflect- ed the mature artistic expression of the Sung period, where the emphasis was no longer on complexity of manufacture, but on the simple and refined beauty of natural stone. The preference has en- dured up to the present day.

Clearly, not just any stone could be used to make an inkstone because of aes- thetic and practical considerations. Ac- cording to the History of the Inkstone written by Mi Fei (¦Ìªè ), the Sung schol- ar, calligrapher, and fanatic collector of inkstones, stones from thirteen different regions of China were used in the manu- facture of inkstones. In addition, ink- stones were embellished with carving, both with designs and calligraphy. Elevated from the status of utilitarian items, good inkstones were cherished as works of art in themselves. It was during the Sung that the inkstone, along with brush, inkstick, and paper, was given the accolade of the "four treasures of the scholar's study."

Not all stones are created equal, and of all the areas which produced inkstones during the Sung, three were considered to be the best: those from Tuanchou ( ºÝ¦{), Hsichou (¾ù¦{), and Ch'ingchou ( «C¦{). Before long, stones from Ch'ing- chou were unobtainable, and those from Yaoho (¬«¦{) were considered equally valuable. Together with the Ch'engni inkstone, which was still produced in limited numbers during the Sung, the four were crowned as China's most famous inkstones. Today, a millennium later, these are still considered the best by antique collectors. Moreover, the ink- stones from the area formerly known as Tuanchou and Hsichou are still being produced by contemporary craftsmen.