noun
collation of sections; gathering (bookbinding)
Technical bookbinding term for checking the order of folded sections (signatures) before binding, or the process of gathering them.
製本の前に丁合を確認する。
Check the collation of sections before binding.
丁合作業は手作業で行われることもある。
Gathering work is sometimes done by hand.
製本 is the broader process of bookbinding, while 丁合 specifically refers to collating or gathering the folded sections.
Compound of 丁 (chō, 'leaf' or 'sheet') and 合 (ai, 'matching' or 'joining'), referring to the matching of printed sheets in bookbinding.