Mine, Mine, Mine! Let bookplates do the job for you or your child. It’s the original passive-aggressive note.
These lovely bookplates are available through Etsy artists Denise Ann Simon and The Black Apple.
As with all Etsy artists, when the products sell out, don’t hesitate to contact them directly and ask when a new batch will be available. Alas, that is but one delightful ingredient in the “secret sauce” of Etsy.