Study of black glaze and sauce glaze porcelains from Dangyangyu kiln during the Song and Jin Dynasties, China

Abstract

In the Song and Yuan Dynasties of China, numerous renowned kilns simultaneously employed black glaze and sauce glaze porcelain; however, limited research has been conducted on the differentiation of process systems and the potential existence of a transforming relationship between these two types of porcelains from the same kiln. In this study, the black glaze, sauce glaze and flambé (窑变, Yaobian) glaze porcelain from Dangyangyu kiln during the Song and Jin Dynasties were selected to compare their optical characteristics, firing and formula process via OM, LRS, SEM-EDS, XPS, DIL and EDXRF methods. The research reveals that notable distinctions exist in the glazing process between black glaze and sauce glaze porcelain; while the former demonstrates thicker glazing techniques, the latter showcases thinner glazing techniques. Sauce glaze porcelains undergo firing at high temperatures within strong reducing atmospheres and differs from black glaze in terms of their formulation processes. The sauce glaze is composed of high Al clay with a low flux content, making it a calcium-alkali glaze. On the other hand, the black glaze has a higher flux content and falls under the category of high calcium glazes. Through the investigation of flambé glaze, it was observed that despite a thicker black glaze layer does not promote Fe enrichment on the glaze surface, however, when the flux content in the glaze is lower, meanwhile accompanied by a high temperature and strong reducing atmosphere firing process, the glaze exhibits a dynamic tendency towards the formation of sauce coloration.