He Jian Wang Xi, clay impression, Seal of Prince of Hejian, Western Han Dynasty (202 BCE—8 CE). Length 3.25 cm, Width 3.4 cm. Gift of Mr. Sun Ding © Shanghai Museum 

One of the early uses of seals was to affix to the sealing clay to prevent illicit opening by others when bamboo and wood slips, or other materials, were delivered. This clay impression is a Western Han dynasty relic. The owner of the seal was the Vassal King Liu Pijiang of Hejian, who was enfeoffed in the early Han dynasty.