Bound books can be “case bound” – which is the glueing together of pages – and this is a very pretty method, if you want to upgrade computer-printed pages. I used this method to turn all my three online classes into books; PDF files and e-books can take form in this way, too.
A lot more beautiful, however, are oversewn books! There are so many possibilities! I especially enjoy working with my hand-dyed threads, of course.