[2] As the name suggests, the strokes of a character are "folded" or "stacked" back on themselves,[2] such as to fill the available space.

[5] Depending on the complexity of the character and space constraints of the seal face, however, the number of "fold" layers did not always equal nine, but could be as few as six[2] or as many as sixteen.

[d][3] Nine-fold seal script was developed during the Song dynasty (960–1279).

[1] One of the earliest examples of folded seal script is the "Seal of the Inner Court Library" used by the court of Emperor Huizong of Song (reigned 1100–1126) on artworks in the imperial collection.

[5] The Mongol-led Yuan dynasty developed a seal-script form of Phags-pa influenced by Chinese nine-fold seal script,[1][5] and the Manchu-led Qing dynasty did the same for the Manchu script.