About 906–618 BC, China used fish, ox, and stag horns to produce adhesives and binders for pigments. Animal glues were employed as binders in paint media during the Tang Dynasty. They were similarly used on the Terracotta Army figures. Records indicate that one of the essential components of lampblack ink was proteinaceous glue. Ox glue and stag-horn glues bound particles of pigments together, acting as a preservative by forming a film over the surface as the ink dried. The Chinese, such as Kao Gong Ji, also researched glue for medicinal purposes.