Many of the most iconic films in cinematic history — Casablanca, Gone With the Wind, Citizen Kane — were recorded on nitrate, the earliest form of motion picture film, yet the material has a terrible reputation. Used from the late 1800s through the 1940s, nitrate film was incredibly flammable and caused some major fires in movies theaters. These tragic chapters in cinematic history have been revisited in films such as Cinema Paradiso, Inglourious Basterds, and The Artist. Later, once nitrate film was phased out, many archives were intentionally burned, simply to destroy the hazardous material.

But film archivists see nitrate in a different, less fiery, light. Aside from being an important ancestor of all the forms of film that came after it, nitrate is lauded for its luminous, high-contrast images, resulting from an emulsion that was rich in silver and the film’s excellent transparency. And if it’s handled properly, the film is perfectly safe. For all these reasons, the George Eastman Museum in Rochester, New York is gearing up for the third Nitrate Picture Show, which will take place from May 5–7, 2017. Passes for the weekend go on sale at midnight on Monday, December 12.

“It’s kind of a mystery how nitrate film has endured, because people are so afraid of it,” said Deborah Stoiber, technical director of the festival and collections manager in the museum’s Moving Image department, which houses more than 100,000 cans of nitrate in its vaults. Those cans comprise more than 6,000 titles, many on extended loan from Warner Brothers. The museum’s Dryden Theatre is one of only three theaters in the US with the legal safety measures in place to screen nitrate films, and the only such theater outside of California.

The Nitrate Picture Show is intended not only to give audiences an authentic cinema experience from the past, but also “to dispel the myth that all nitrate is scratched, jerky, falling apart or otherwise not worth keeping,” Stoiber said. The films that are shown at the festival are in pristine condition, and visitors can see and touch such nitrate prints up-close. People are often astounded by the quality, according to Stoiber.

Nitrate film is also known as celluloid or nitrocellulose film base. The compound nitrocellulose was used to make gun cotton, and English chemist Alexander Parkes is believed to have pioneered its use in an early form of plastic. Scientists in the US, including those at the Eastman Company (later Eastman Kodak Company) continued refining the formula to produce their own plastics. In addition to film stock, this plastic was used in everyday products, such as collars, crinolines, shoe heels, billiard balls, and hair combs. But the plastic caught fire easily when exposed to heat, and projectionists had no idea that a lit cigarette could be a serious hazard in the projection booth. And once a nitrate film is started, it produces its own oxygen, making it impossible to extinguish. In 1896, just one year after the first-ever public exhibition of motion picture film, the first nitrate fire on record occurred in London, and it was attributed to “a careless assistant.” The following year, a notorious nitrate fire killed more than 125 members of the social elite of Paris.

More fires followed over the years, resulting in public paranoia and increased safety measures. In 1937, Fox’s film vault in New Jersey went up in flames. In the early 1950s, Kodak stopped producing nitrate, and instead acetate, or “safety” film, became the dominant film stock. But fears persisted. In the ‘60s, there was a major nitrate fire at MGM’s film vault in California. Ultimately, some film companies decided nitrate was too expensive to store and, after copying the films onto new stock, burned their archives in order to reclaim the silver. Fire departments held collection drives for nitrate films and burned them. To this day, the film is illegal in Manhattan and Washington, DC. The nitrate prints that have survived all of this burning were often saved by film enthusiasts or film archivists who were instructed to burn them but saved them instead.

At the Eastman Museum’s Louis B. Mayer Conservation Center, which was built in 1989, nitrate films are stored in 12 separate above-ground vaults (so, if there’s a fire in one, the entire collection won’t be lost). The vaults are kept at 40 degrees Fahrenheit and 30 % humidity to keep the film from decaying and shrinking. Films in very fine condition — less than 1% shrinkage — are projectable, though the opportunity to see screenings are limited.

“It’s fascinating that original nitrate film prints can be both perfectly preserved and still projectable, something we will hardly be able to say about our current digital film technology 70 years from today,” said Jurij Meden, the museum’s curator of film exhibitions and a member of the Nitrate Picture Show executive team. (In the world of digital film, file formats and hardware quickly become obsolete, posing a challenge for preservationists.) The schedule of films is kept a secret until the opening day of the festival, because, Meden says, the event is more about “the splendid quality of the medium” than about the titles.

George Willeman, nitrate vault manager at the Library of Congress’s National Audio-Visual Conservation Center in Culpeper, Virginia, spent more than three decades working with nitrate film before he first saw it projected earlier this year, at the second annual Nitrate Picture Show; it was the fulfillment of a dream for him. The films screened at the festival are loaned from institutions around the world, including the Library of Congress and Martin Scorsese’s personal collection. Since its start in 2015, the Nitrate Picture Show has inspired other institutions to create similar programs celebrating nitrate film.

“We want people to make up their own minds about nitrate: Is it dangerous or is it beautiful?” Stoiber said. “To me, it can be dangerous, but it’s mostly beautiful.”

The third Nitrate Picture Show which will take place at the Eastman Museum’s Dryden Theatre (900 East Avenue

Rochester, New York) May 5–7, 2017. Passes for the weekend go on sale at 12:01AM (ET) on Monday, December 12.