One thousand years before Europeans learned to make porcelain, the Chinese were producing exquisite examples of what they call taoci. Taoci can be translated two ways, meaning either "pottery" or "porcelain". Chinese clay and stoneware products with no compact sinter are considered "pottery", whereas "porcelain" refers to clay and stoneware items baked under higher firing temperatures with a more compact sintered matrix. Because traditional Chinese porcelain has developed over many hundreds of years, it is important to supplement academic indexes with both conventional identification techniques and technological advances when classifying taoci. The following paragraphs identify markers specific to important developmental periods of traditional Chinese porcelain and can be used as guidelines for novice collectors.
Tang Dynasty (618 - 907 C.E.)
In the early Tang dynasty, celadon and white porcelain were unglazed and globular in form with a flat bottom. As the period progressed, a small number of footed vessels were produced and firing after glazing became more common. Typical forms from the Tang Dynasty period include zoomorphic vessels, multi-mouthed bowls, vessels with petaled rims, sancai or tri-colored porcelain, and roped vessels. The most common ornamentations include applied motifs (such as dragons and phoenixes), incised floral tendrils and figural work, geometric patterns, stippling and crosshatching. The Yue kilns can be credited with making the finest Tang Dynasty celadon porcelain, and are best known for using a compact matrix in combination with fewer blow holes in order to produce a clean and evenly-distributed glaze. Spur marks, resulting from matrix supports, are commonly found both within and on the exterior of vessels from this period. Matrices should be translucent or opaque and yellow, yellow-green, grey, or light grey in color.
North and South Song Dynasties (960 - 1127 C.E., 1127 - 1279 C.E.)
Longquan celadon was the most commonly produced type of porcelain during the Song dynasties, typified by pieces from the Jincun kiln in Longquan County, Zhejiang Province. The matrix for Longquan celadon can be either white or black, with white being the most common. Longquan celadon made from a white matrix should have flint-red or cinnabar edges. A lime glaze, characterized by its dark color and translucence, was used primarily during the North Song Dynasty. A lime base glaze is most commonly found on vessels produced during the South Song Dynasty.
Yuan Dynasty (1271 - 1368 C.E.)
During the Yuan dynasty the Longquan porcelain industry continued to develop. Kilns from this period produced a greater number of large pieces than they had previously. Common ornamentations from the Yuan dynasty include incised motifs such as the cloud-dragon, lychee fruit, peony, chrysanthemum petals, and lotus leaf, molded appliques, decorative borders, and geometric patterns. Narrative scenes were also very typical. The painting style used during the Yuan dynasty was evocative, but very free-form; it is common to see decorations escaping their borders. The primary glaze used during the Yuan dynasty was blue and white. The glaze could be applied either as blue on a white matrix or white on a blue matrix. The latter is the most common method, while the former was used mostly on larger vessels and plates with petaled rims. Vases from Gao'an County exemplify "traditional" Yuan dynasty blue and white porcelain. Compared to examples from later periods, Yuan dynasty blue and white is of higher quality.
Ming Dynasty (1368 - 1644 C.E.)
An imperial porcelain factory was established at Jingdezhen at the beginning of the Ming dynasty and quickly took over as China's capital for porcelain production. The kilns at Jingdezhen produced a large number of imperial wares, all stamped with the reign mark of the emperor they were produced under. Many innovations were made during the Ming Dynasty that have since become representative of fine period porcelain, such as doucai (contending colors) and wucai (five-color) vessels. In the late Ming Dynasty, the porcelain industry shifted toward export pieces and household wares and the quality declined. Household wares from the period often featured a grey glaze with an unglazed, rough foot.
Qing Dynasty (1644 - 1912 C.E.)
Porcelain production reached its highest point during the Kangxi, Yongzheng, and Qianlong periods of the Qing Dynasty. The factory at Jingdezhen continued to be a leader in porcelain production. Due to strict imperial regulations and distinct formulas, the quality of pieces made at Jingdezhen was much higher than those produced by other period factories. Blue-and-white wares were still very common. The most important contribution made to Chinese porcelain during this period, however, was the creation of opaque over-glaze enamel colors. These colors allowed for varied hue gradation, which has become a hallmark of fine Qing dynasty porcelains.