Then an electrical technician, Cassagnes came upon the Etch A Sketch idea in the late 1950s when he peeled a translucent decal from a light switch plate and found pencil mark images transferred to the opposite face, the Toy Industry Association said.

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To further hone the image, engineers use a technique called optical proximity correction, which uses oddly shaped bars, notches and other distortions that are cut into the chrome template on the quartz plate to trick light waves into making a more precise pattern (see left).

FORBES: Trick Of The Light

To further hone the image, engineers use a technique called optical proximity correction, which uses oddly shaped bars, notches and other distortions that are cut into the chrome template on the quartz plate to trick light waves into making a more precise pattern (see chart).

FORBES: Trick of the Light

The third objective, efficient design, involved sandwiching the nanostructured bismuth telluride between two copper plates and then enclosing the upper plate (the one coated with the light-absorbing oxides) and the bismuth telluride in a vacuum.

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Most photomasks are created by etching away a thin film of light-blocking chrome from the surface of a quartz plate.

FORBES: Trick of the Light

The first time I shed the heavy plate armor and tried on the Black Leather suit, I realized how much more fun light armor was.

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