... "New Photosensitive Hydrolyze Technology".can be written on any materials;Even if the children draws on wallpaper,cloth or sheet,you just wipe ... normal condition.Let you shouldn't bothered with the children's doodling on anywhere.3.Repeatly used,economy and beneficalV-CLEAR doodling ... and easy wiping,repeatedly used,and economy.SO let your children in the light-hearted doodling,enjoy the endless fun ...