Wu Yi Seal, Western Han Dynasty (202 BCE—8 CE). Jade. Length 2.3 cm, Width 2.3 cm, Height 1.65 cm. © Shanghai Museum.

Bird and insect script was a kind of decorative text popular in the Han dynasty, in which the outlines of the images of the outlined fish, birds, insects and other animals were taken as strokes. This jade seal is the masterpiece of the bird-and-insect scripted seals of the Han dynasty. With deft layout, the seal looks complicated but not messy. The abstract images of flying birds and swimming fish look lively and vivid, reflecting the outstanding design and carving techniques of the time.