Back when I was a teacher, at my very first school we had a fabulous librarian. She’d been a librarian for several years, so she had all sorts of great ideas she’d instituted.
One of those was a shelf marker.
When the kids would go to look for books they’d grab a shelf marker, and put it in-between the two books before they pulled out the book they wanted to look at.
Then they would leave it there, while they looked through their book. If they wanted to keep the book, then they’d pull it out and move on. If not, they knew where their book would go back and could put it back in its correct spot.
As you can see, my kids were WILD for the idea!
Ours came from my most recent painting project. I asked the Home Depot guy if I could grab a handful of extra paint stirrers, and he had no problem with it. As I stirred the paint I slowly used each one, carefully dipping both ends in the paint, so both ends were painted. Now, I didn’t get all of them, but most of them are ready to be decorated by willing kiddos.