Have you ever sat through a holiday movie and wondered how they make it snow when ... it really isn’t? Don’t worry, you’re not alone. Different methods have been used over the years to make the fake snow seem real in movies. Here’s a quick breakdown.

What do movies use for fake snow?

Up until the late 1920s, Hollywood used cotton as their real snow alternative until it was deemed a fire risk by the Los Angeles Fire Department. Go figure. Many theaters also used white-painted cornflakes to simulate snowflakes, which turned out to become a loud and messy method.

Here are some of the ways the movie-makers continued to innovate over the years for health and safety precautions, as well as convenience, budget and on-screen believability.

  • 1925: A simple batch of salt and flour was the first of many famous artificial snow techniques started in 1925 for Charlie Chaplin’s Gold Rush. Timber (reportedly a quarter-of-a-million feet), burlap and chicken wire were used to create the film’s mountains.

  • 1930s and 40s: Before it was discovered how dangerous it could be, industrial-grade chrysotile (otherwise known as asbestos) was used in films such as The Wizard of Oz and Citizen Kane. Hollywood wasn’t the only industry that mistakenly used the dangerous material, as asbestos used to be sold for Christmas tree decorations as well during this time.

  • 1946: In order to avoid a cleanup problem on the set of It’s a Wonderful Life filmmakers mixed Foamite (the material used in fire extinguishers) with sugar and water. Then, they pumped nearly 6,000 gallons of (then) state-of-the-art fake snow through a wind machine to create the fictional place we all know and love as Bedford Falls.

  • 1965: Marble dust was used in David Lean’s Dr. Zhivago. First, the crew applied a layer of wax and cold water, sprinkling the marble dust across the set to create a magical form of faux snow.

  • 1978: For outdoor film scenes where large amounts of snow are needed, like Superman, old salt was used. This proved to be bad for the environment, so salt didn't last long.

  • 1984: ‘Snowcel Artificial Snow’ saw its first big-screen debut during Company of Wolves. A paper-based snow product used for recreating heavy, drifting snow or scenarios where interaction with the fake snow is required—SnowCel quickly emerged as one of the widely used methods for filmmakers to create snow in movies.

  • 2002: In more recent years, computer-generated imagery (CGI) has taken over as the predominant method for fake snow. But that doesn’t mean it’s gotten easier. Some studios, like Disney for example, have put resources into researching the most effective ways to animate snow. Ice Age was nominated for Best Animated Feature at 75th Academy Awards, in part to its achievements in winter visual effects.

Keep reading: Animation lesson from Pete Docter—director of “Up” and “Monsters, Inc.”