What do the dictionaries say?

According to Larousse : A drawn or engraved vignette that bibliophiles paste on the inside back cover of their books, bearing their motto or name. According to Robert: An inscription or vignette affixed to a book to indicate its owner. According to Wikipedia: (from the Latin *ex libris meis* , "from my books") is a small engraving or print pasted inside a book, by which the owner marks their possession. Traditionally engraved in intaglio, it may mention the owner's name, coat of arms, motto, or various symbols and motifs of their choice. It is therefore a personalized engraving that a collector or bibliophile pastes on the endpaper (the inside of the cover) or on the title page of their books, as a mark of ownership.