"Ex Libris" is a Latin phrase meaning "From the library," but it can also be used to describe bookplates themselves. What's a bookplate? Usually adhesive-backed with a space to write your name, it's a small paper or sticker that goes in the inside cover of the books in your personal library. It's a fun way to show your personality (and also make sure any beloved titles you loan will make it back to you.
Just want to showcase your love of books and yarn via vinyl stickers - find that here too.