The Harvard library has 2 books that are bound in human leather. They date back to the 17th century. There was another book that said it was bound with human leather, but it was a practical joke by the author.
https://roadtrippers.com/stories/harvard-discovers-three-of-its-library-books-are-bound-in-human-flesh?lat=40.80972&lng=-96.67528&z=5