$300K campaign to rescue Dorothy’s ruby slippers

File- This Nov. 9, 2001, file photo shows the sequin-covered ruby slippers worn by Judy Garland in "The Wizard of Oz"  at the offices of Profiles in History in Calabasas, Calif. Smithsonian Museum officials started a Kickstarter fundraising drive Monday, Oct. 17, 2016,  to repair the iconic slippers from 1939’s “The Wizard of Oz” and create a new state-of-the-art display case for them at the National Museum of American History.  (AP Photo/Reed Saxon, File)
File- This Nov. 9, 2001, file photo shows the sequin-covered ruby slippers worn by Judy Garland in "The Wizard of Oz" at the offices of Profiles in History in Calabasas, Calif. Smithsonian Museum officials started a Kickstarter fundraising drive Monday, Oct. 17, 2016, to repair the iconic slippers from 1939’s “The Wizard of Oz” and create a new state-of-the-art display case for them at the National Museum of American History. (AP Photo/Reed Saxon, File)

WASHINGTON (AP) — It will take more than three clicks of the heels to preserve the ruby slippers that whisked Dorothy back to Kansas at the end of “The Wizard of Oz.”

The slippers, which for more than 30 years have been one of the most beloved items at the Smithsonian’s National Museum of Natural History, were crafted almost 80 years ago by the MGM Studios prop department. Like most movie props, they weren’t built to last. Now, the frayed shoes aren’t even ruby-colored anymore — they’re more like a dull auburn.

On Monday, the Smithsonian asked the public to help save the slippers, launching a Kickstarter campaign to raise $300,000. In addition to keeping the shoes’ color from deteriorating further, the money will go toward a technologically advanced display case that will preserve them for future generations.

The Smithsonian’s museums are federally funded, but the institution frequently solicits private and corporate contributions for major projects that its budget doesn’t cover. This is the Smithsonian’s second Kickstarter campaign. In 2015, the National Air and Space Museum raised $700,000 through the crowd-funding site to preserve the spacesuit that Neil Armstrong wore when he walked on the moon.

“This particular pair of ruby slippers really belongs to the American people, and so we thought as we sought support that we would invite the public to join us on this journey to help preserve them for the next generation,” said Melinda Machado, a museum spokeswoman.

The shoes are the most recognizable prop for the beloved 1939 musical, their deep red hue dazzling audiences when the movie made its dramatic transition from black-and-white to Technicolor. They have been on near-constant display since they were anonymously donated to the museum in 1979.

Preserving them is more complicated than it might appear, Machado said. The slippers contain a dozen different materials. The gelatin-based sequins are a relic from the infancy of plastic. They also include glass beads and red felt on the soles that was used to muffle their sound when Judy Garland wore them during dance sequences.

“We’re going to have to do a lot of scientific research to come up with a treatment plan that is compatible with all of the different materials,” Machado said.

As of Tuesday morning, donors had pledged more than $38,000 on Kickstarter. If the museum does not reach its $300,000 goal in 30 days, no one will be charged. Donations start at $1 and, depending how much they give, contributors can receive rewards including T-shirts and tote bags created by William Ivey Long, a Tony award-winning costume designer.

Here are five things to know about the famous relic:

– THEY’RE NOT THE ONLY PAIR: At least seven pairs of slippers were made for the movie, and four pairs are known to exist. The Smithsonian’s pair was donated anonymously in 1979 after being sold at auction in 1970. Two other pairs are owned by private collectors, including a pair purchased by Leonardo DiCaprio and Steven Spielberg for display at the Academy Museum of Motion Pictures, which opens next year in Los Angeles. A fourth pair was stolen from the Judy Garland Museum in Grand Rapids, Minnesota, in 2005, and remains at large.

– THEY’RE MISMATCHED: One shoe is wider than the other, and there are other subtle differences in their shape and construction. Each has Garland’s name scrawled on the inside. One is marked as “#1,” the other as “#6.”

– NO RUBIES: The shoes are made from about a dozen different materials, including wood pulp, silk thread, gelatin, plastic and glass. Most of the ruby color comes from sequins, but the bows of the shoes contain red glass beads. They began as ordinary shoes that were dyed red, and a netting with the sequins was fitted for them and sewn on. They have felt on the soles to muffle their sound for dance sequences.

– NOT MADE TO LAST: The shoes are nearly 80 years old, and like most movie props, they weren’t built to last. During their time at the museum, the color has faded significantly from exposure to light and moisture. Some of the sequins have no red plastic coating left and are no longer translucent.

– COSTLY PRESERVATION: If the Smithsonian successfully raises $300,000, most of the money will go toward scientific research and construction of a special case that will keep them from deteriorating further. The shoes will also be cleaned, but nothing will be done to enhance their color or repair them with newer materials.