You are probably too young, but if you are of a certain age and were even vaguely bookish as a kid, you were probably given a set of personalized bookplates by a much-loved aunt at some point. That is how I received my first set. Perhaps they had a dog on them, or baseball players, or a boy sitting in a window with a large book on his lap.
Bookplates, also known as Ex Libris, are a small decorative label pasted into a book, usually on the inside front cover, to indicate its owner.
Bookplates typically had your name, or a motto, coat-of-arms, crest, badge, or some motif that related to the owner of the book. The name of the owner usually follows an inscription such as: “from the books of…” or “from the library of…”, or in Latin, “Ex Libris”.
Even when I was little, which was a very long time ago, I knew that bookplates were a particularly passive-aggressive way to indicate that you owned something: a beautiful piece of art that acted as rigid reminder of what was mine and what was yours. More elegant than “you can borrow it, but bring that book back ”
People in the Middle Ages began to mark ownership with simple inscriptions. In 15th-century Germany bookplates took their more modern, pre-made decorative form.
In the 19th and 20th century, bookplates became recognized as a minor branch of higher art. You may have come across one if you have ever bought a dusty old book from a used bookstore. They are not to be confused with a “bookmark” on your Internet browser history, although they can be quite naughty.