You shall not pass!
Another example of how being a parent often means spending your time asking your children not to waste stuff. It’s a great milestone when they finally start wiping their own bottoms, but you’ll instantly find your toilet paper bill shooting through the roof.
All you need though, to save the acres of trees being shoved down the pan, is this sticker on the wall, showing them how far (and no further) they should pull the roll. With a cute little Lord of the Rings joke thrown in.