Obviously I don't make much money binding books, but it's very cozy work. I did simple, necessary things for the university. We bound precious pamphlets in a way that preserved them. Architectural works and something of the Latin poets. Those made of vellum are usually just rotten in the back.
Vellum's a wild thing, the hide of a calf or a lamb.
It's treated with acid. The pages are falling apart. You take them out if you can and you wash them, deacidify them in a certain solution. Then you fold them together and press them in your press. Some of my private customers have very splendid collections, beautiful bindings you'll never see again.