What is "seal script"

n. 1 (context usually English) (altname: small seal script) 2 (context also English) all forms of ancient Chinese calligraphy used for seals and chops, including the Zhou-era large seal script

Seal script is an ancient style of writing Chinese characters that was common throughout the latter half of the 1st millennium BC. It evolved organically out of the Zhou dynasty script, arising in the Warring State of Qin. The Qin variant of seal script became the standard and was adopted as the formal script for all of China in the Qin dynasty, and was still widely used for decorative engraving and seals (name chops, or signets) in the Han dynasty. The literal translation of its Chinese name 篆書 (zhuànshū) is decorative engraving script, because by the time this name was coined in the Han dynasty, its role had been reduced to ceremonial inscriptions rather than as a standardized script.