noun
signature; print signature
Technical term in bookbinding and printing: a mark or letter printed on the spine fold of a section (signature) to guide collating and binding.
製本作業では、背丁を確認しながら折丁を重ねていく。
In bookbinding, the signatures are stacked while checking the print signatures.
この本の背丁は、各折丁の背に小さく印刷されている。
The print signatures of this book are printed small on the spine of each section.