Existing comment:
Before the advent of the mechanical printing press, hand written books were precious and uncommon enough to discourage casual lending, but after the invention of the press, there was a sudden proliferation of books, and lending became more common. The use of a bookplate could help secure the return of the owners prized possession.

"Please return this book; I find that though many of my friends are poor mathematicians, they are nearly all good bookkeepers."
-- Sir Walter Scott
Proposed user comment: