CHICAGO (CBS) — It’s one of the scariest buildings in Chicago: the Zagone Studios monster-mask studio on the Northwest Side.

CBS 2’s Ed Curran was brave enough to go inside to see how they create the frightening faces of Halloween.

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Zagone Studios is one of the biggest, most respected mask-makers in the world. Phil Zagone and his brother started the company 40 years ago, in a garage.

His kids – and now, their kids — run the company.  Their popular innovation is a soft mask that flexes as your jaw moves up and down.

Tony Zagone, wearing an Old Man mask, hisses: “Get off my grass! I hate kids!”

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In a normal voice, he explains, “Once you put it on, you’re in character.”

Every mask is made in Chicago, using U.S. materials.

“Every step of the process is done by hand: They’re hand-poured, hand-cut. Every tooth here is hand-painted with a dry brush, and then they’re spray-painted,” Tony Zagone explains.

It starts by filling a plaster mold with latex. After a few minutes the excess is poured off, leaving a thin layer of rubber. After drying overnight, the mask is peeled out, to be detailed by talented artists and finishers.

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Because their masks are hand-made, Zagone Studios is busy filling last-minute orders from shops around the world.