noun
bound book; codex
Refers to a book with pages bound together, typically contrasted with scrolls or other formats. Common in library and historical contexts.
図書館には古い冊子本がたくさん保管されている。
Many old bound books are kept in the library.
本 is the general word for book; 冊子本 specifically emphasizes the physical format of being bound.
Compound of 冊子 (sasshi, 'booklet') and 本 (hon, 'book'), both Sino-Japanese elements. The exact historical derivation is uncertain, but the term clearly refers to a book in codex form.