How It's a Wonderful Life devised a new form of fake snow that revolutionized the medium

Imagine Jimmy Stewart's George Bailey running down the streets of Bedford Falls in the snow wishing that wonderful old Building & Loan a Merry Christmas… only with more crunching noise.

In the early days of Hollywood, movie studios often used bleached cornflakes as a substitute for snow (or even cotton and—yikes!—asbestos), requiring redubbing for close-up wintry scenes. It also didn't allow for footprints, tire tracks, and the like to appear in the snow, which would help sell the scene.

That wouldn't fly for director Frank Capra's 1946 melancholy yuletide classic It's a Wonderful Life, which follows the kind-hearted George Bailey, who gets a holiday life lesson when a guardian angel, Clarence (Henry Travers) appears and shows him the bleakness of a world where he'd never been born.

"Capra wanted to be able to shoot live dialogue in close-ups while snow was falling and he also knew he needed a lot of snow in general," says Jeremy Arnold, author of Christmas in the Movies.

"The snow is vital to the storytelling," he adds. "It conveys not just a joyful Christmas Eve, but also the character's rebirth. It tells the audience George is back in the real world. He's back from this alternate reality; the snow starts falling and we get it right away. And that is a very gentle, cleansing snow."

In need of a solution, Capra recruited RKO special-effects department head Russell Shearman to devise a silent solution to fall and blanket his enormous 4-acre set. The result: a mixture of Foamite (found in fire extinguishers), soap, sugar, and water that could be shot out of canisters at high pressure and gently wafted over the set with a silent fan.

"You could create various types of falling snow from really gentle to wind-driven, and it could be sprayed anywhere on the set in a targeted way," explains Arnold. "That was something that hadn't really been possible because when you're releasing cornflakes, you're basically just dropping them straight down."

This newly devised snow sold the illusion of a frigid town, despite filming in a sweltering L.A. summer (try to spot Stewart sweating). "The heat is the greatest endorsement of the invention," notes Arnold. "Because the snow looks very real. It looks great even in those hot conditions."

Capra also used Shearman's invention to create hard-falling snow. It's a Wonderful Life used more snow than any other film at the time since Lost Horizon, which Capra directed a decade prior and shot by creating real snow and shooting in a giant indoor icehouse. They also supplemented the Foamite, decorating the set in plaster and gypsum to cover the ground, window sills, and so forth. The Foamite mixture was predominantly for scenes where snow was actively falling.

You can witness the ingenious snow in the new 75th-anniversary limited-edition Blu-ray set of the film from Paramount Home Entertainment, who shared the exclusive rare behind-the-scenes photos featured here. The collection also includes recipe cards with cuisine inspired by the film and a host of bonus content, including footage from the film's wrap party.

Though its effect here is certainly memorable, Shearman's invention had an impact that far exceeded this film; it became the industry standard for decades. In 1949, he was awarded a technical achievement Oscar for "simulating falling snow on motion picture sets."

No man is a failure who has brilliant innovations.

A version of this story appears in Entertainment Weekly's December issue, on newsstands now and available to order here. Don't forget to subscribe for more exclusive interviews and photos, only in EW.

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