There are two main ways of book binding. One uses glue/adhesive, the other uses string/wire/tying. I'd assume the bailing wire would be used for the second type

There are two main ways of book binding. One uses glue/adhesive, the other uses string/wire/tying. I'd assume the bailing wire would be used for the second type in a pinch if for some reason duct tape wasn't usable.