You're cutting your books' bindings at between "signatures." Those are the 16-page little booklets bound together to make the big book. Each signature is made b

You're cutting your books' bindings at between "signatures." Those are the 16-page little booklets bound together to make the big book. Each signature is made by folding and cutting a single large sheet of paper coming off the press, if it's a page press and not a warp (paper roll) press. Those 16-page signatures used to be called "octavo" or "8vo" in the early days of printing. This is a time-honored practice in bookmaking. Why shouldn't a very long book be published in multiple volumes? Before modern very- thin and very- cheap paper this was common practice. J. R. R. Tolkien wrote and published the Lord of the Rings as a trilogy because his publisher didn't want to make his work too expensive or heavy for the mass market of post WWII Britain. Go for it. You're not disrespecting the author, the editor, or the printer. And, modern bindings don't really command much respect anyway. (Not books you've borrowed from libraries or other people, duh. That could rile up a librarian or your friends big time.)