Technology of Slip Affecting Carbon Smudging Depth in Prehistoric Chinese Black Pottery: Scientific Analyses and Simulation Experiments

ABSTRACT Carbon smudging and black coating are two main coloration techniques of black pottery, yet the combination of slip and carbon smudging remains unstudied. This research is the first to reveal this black pottery technological process and the mechanism by which slip affects carbon smudging depth. Scientific analyses and simulation experiments were conducted on samples from several archaeological sites in prehistoric China. The results show that unfired clay is first fired and then a slip is applied and subjected to postfiring carbon smudging. Although carbon smudging depth cannot be precisely regulated in single firing, it can be effectively affected in the postfiring process by adjusting the slip thickness, thereby highlighting the carved decorations. Meticulous burnishing helps to preserve the decorations. The surface layer technology is more complex and advanced than that of ordinary black pottery.