Then an electrical technician, Cassagnes came upon the Etch A Sketch idea in the late 1950s when he peeled a translucent decal from alightswitch plate and found pencil mark images transferred to the opposite face, the Toy Industry Association said.
For maximum runtime the switch is held down for ten seconds, activating the lightin dim mode and producing a mild 1.3 lumens of light with an extreme runtime of 480 hours.