Roylco Optical Illusion Rubbing Plates, 7 x 7 Inches, Set of 6

Lay paper over the sturdy plastic plates and rub with crayons or colored pencils. Move the paper and rub again with a second color to create illusions. Press the plate into modeling clay to create a 3D image. Fill the tray with white glue and food coloring to make a sun-catcher; simply peel the resulting mold off and you're done.