Seal of Steward of the House of Prince of Qi
Date: Tang (618-907)
Dimensions: Length 5.65 cm, Width 5.65 cm, Height 3.64 cm
Material: Bronze
From the Sui dynasty, the official seal system came out with new standards. The administrative system replaced the previous officially-titled seals with government seals, which became a tradition of official seals of Chinese society in later dynasties.
The appearances and the ways of using the seals also undertook changes in the Sui and Tang seal systems: the seal inscription was changed to the characters in relief with the enlarged shape and structure and simplified knob; with red ink pad directly affixed on paper.