1) Easy for doodle ,water only, no pollution. 2) Can be used over ... kids. This is painting pad matched with a water pen. Doodle with this water pen only, no need ink , no paint ... be used over and over again, just add water in it.The doodle mat can be used over and over again ... , the doodle area will dry and the color disappeared after a few minutes.Easy for storage and travel. magic water painting