ANSWER: Toys

Etch-A-Sketch

The toy can be considered a simplified version of a plotter. The inside surface of the glass screen is coated with aluminium powder which is then scraped off by a movable stylus, leaving a dark line on the light gray screen. The stylus is controlled by the two large knobs, one of which moves it vertically and the other horizontally. To erase the picture, the artist turns the toy upside down and shakes it. Doing this causes polystyrene beads to smooth out and re-coat the inside surface of the screen with aluminium powder. The "black" line merely exposes the darkness inside the toy. Filling in large "black" areas will allow enough light through to expose parts of the interior.

Matt: CORRECT
Record: 303-244