Optical Illusion Rubbing Plates are versatile and fun for art, design, science, and much more. This hands-on, easy-to-use tool is sure to enhance learning concepts. Add texture to artwork by placing paper over a plate and rubbing with a crayon, marker or pencil to create illusions. Layer designs for more effects. Fill with or press into modeling clay. Sturdy plastic rubbing plates work great with paper mache. Make sun catchers using white glue and food coloring. Simply fill tray and let dry. Peel the resulting mold off, and you're done. Each set includes six rubbing plates and a guide with craft ideas. They are recommended for children ages 4 and over.