I have a pretty old book that has a hard cardboard sleeve that’s really frayed at the corners, so that the bottom part of it is coming off a bit. What kind of glue would you use? I want to keep it from fraying again or damaging/having weird effects on the material over time.
I’d recommend going to a nearby library, asking the librarians about their own book mending process and getting their advice. Most do their own book repair.