scrolls because they were rolled up, bound, and tagged for identification. The practice of using scroll pouches called ji (帙) to hold five to ten scrolls had been in existence (Shuowen Jiezi defines the character as "book clothes"), but paper had not been invented by Cai Lun until 13 years after Ban Gu's death. The earliest form of back-bone binding of books, the butterfly binding (蝴蝶裝), was not invented until around 1000. Contents Research Commentaries on "Yiwenzhi" were done by Yan Shigu (581–645) and Wang Yinglin (王應麟; 1223–1296). Modern researchers on the topic include Gu Shi (顾实), Chen Guoqing and others. Comparison to the Pinake of Alexandria The Hanshu Yiwenzhi catalogued the Former Han Imperial Library holdings under "6 domains, 38 classes, 596 families; 13,269 scrolls in all" (大凡書，六略三十八種，五百九十六家，萬三千二百六十九卷。) concludes the treatise. An estimated 20% of the titles are extant today. This compares favourably with the estimated 10% survival of the Pinakes titles that consisted of works in Greek, Egyptian, Aramiac, Hebrew, Persian, and other languages, in the Great Library of Alexandria of the 3rd century BCE, which according to one tradition, at one time held some 120,000 parchment scrolls and papyri. References Footnotes Works cited External links Chinese Text Project 《藝文志》 Chinese classic texts