R.E. Taylor Poster Award at ISA - Yan Zhang

The archaeological and scientific analysis of blue-decorated ceramics in the Tang (618-907 CE) and Song (960-1279 CE) dynasties

Yun Zhang and A. Mark Pollard, University of Oxford

The archetypal Chinese blue-and-white porcelain is decorated with underglaze cobalt pigment(s). Its production, use and trade boomed from the 13th to 20th century CE. Remarkably, the Tang dynasty had already witnessed the earliest known use of cobalt pigment in Chinese ceramics, in Tang sancai, from the second half of the 7th century CE. And some excavations show that blue-and-white porcelains had been produced and used in the late Tang and Song dynasties, around between the 9th and 13th century CE. This paper reviews studies of Tang and Song blue-and-white porcelains, both archaeologically and scientifically, based on published data, and compares blue-and-white with sancai. Thirty-nine Tang blue-and-white wares have been found from one kiln – Gongyi in northern China; two ports – Yangzhou in China and Siraf in Iran; one shipwreck – Belitung shipwreck in Indonesian waters; and one tomb – Zhengzhou tomb near the Gongyi kiln. Yangzhou, which contains the greatest number of Tang blue-and-white sherds of all the five places, numbering twenty-seven, witnessed the establishment and prosperity of thousands of foreign merchants. These findings identify Tang blue-and-white as export ceramic related to the Maritime Silk Road or suggest it was produced for international merchants and visitors in China for daily use or personal collection. The use of cobalt on high-fired ceramics was not common in northern China nor outside China after the Tang period (618–907 CE). Four Song blue-and-white sherds were discovered in the rammed earth layer of two pagoda foundations in Zhejiang. These pagodas were constructed in 977 CE and in 1265 CE, respectively, which suggests that these blue-and-white porcelains were produced at or before these times. The findings reflect the connection between Song blue-and-white and Buddhist culture. Furthermore, there are debated about three Song blue-and-white wares found in the Jizhou kiln since their date was inferred to be Song (960-1279 CE) or Yuan (1271-1368 CE). These two pagodas and one kiln both located in southern China. All Tang and Song blue-and-white porcelains are vessels and the motifs on them are plants, insects, a child, geometric and combination patterns. Palmette and lozenge motifs were traditional Middle Eastern decoration on many Abbasid ceramics. These exotic motifs of Tang blue-and-white porcelains show the influence of Middle East taste. 

Additionally, we reanalyse and discuss the previous scientific evidence of Tang and Song blue-and-white, including body, glaze, and cobalt pigment to reveal the origin of materials and technology of early blue-and-white porcelains. Tang blue-and-white is porcelain or stoneware decorated with cobalt-blue decoration under or on a lime/lime-alkali glaze. The raw pigment of Tang blue-and-white was possibly inherited from sancai, probably from the Middle East, and the biscuit body and high-fired clear glaze were provided by white porcelain. The proportion of R2O (K2O and Na2O) in clear glazes and the firing temperature of Song blue-and-white are higher than Tang blue-and-white. Significantly, Song blue-and-white may utilise native cobalt ore containing high manganese, which possibly was from Zhejiang, southern China.