7 things you never knew about the ruby slippers from ' The Wizard of Oz'

$1 Million Reward Offered For Stolen Ruby Slippers
$1 Million Reward Offered For Stolen Ruby Slippers

There are too many iconic pairs of shoes to declare one top dog, but right up there at the top? The ruby slippers from The Wizard of Oz, definitely. The glitzy heels are known globally and have inspired both theft and their own movie (more on that last point in a second). The new documentary, debuted at this year's SXSW festival, is aptly titled The Slippers and pulls back the curtain on the shoes and how they helped create the market for movie memorabilia. The sparklers helped start the Hollywood collecting craze, a cottage industry that sees big numbers—one of Scarlett O'Hara's gowns from Gone With the Wind sold at auction last year for $137,000 after initially being purchased for, oh, $20.

ruby slippers
ruby slippers

For a more thorough look at the ruby shoes, we asked The Slippers director Morgan White to share some of the fascinating facts he learned while putting the movie together.

No one actually knows how many pairs were created for the movie.

"There are four known pairs in existence today, five if you count the Arabian test shoes that never made their way to the screen," White revealed (the Arabian version have slightly upturned toes). "Nobody knows how many pairs of shoes were created for the film, as the studio records were destroyed many years ago."

They require special care at the Smithsonian.

The pair of shoes that lives at the Smithsonian National Museum of American History is a hot ticket. "They are second only to 'the Star Spangled Banner' in foot traffic and draw so many visitors each year that the carpet surrounding their display has to be changed regularly." The Smithsonian's set have felt-covered bottoms, modified to muffle the sound of Dorothy's dancing.

The shoes in the original story were silver.

The book the movie was adapted from had silver shoes, not red. The decision to make the change (using rich burgundy sequins no less) was likely due to a desire to ensure they popped on screen. "The film was shot on a special Technicolor process that was very expensive, and MGM studio chief Louis B. Mayer ordered them changed to something more colorful."

They were lost prior to being auctioned off in 1970.

The pair that now lives in the Smithsonian—and started the craze for collecting—was sold for $15,000 in 1970. Before they could hit the auction block they had to be located though, a feat that proved difficult. "During the auction preparations nobody could find the shoes. It took costumer Kent Warner months to find them among the 450,000 costumes that were there," White told us. "Eventually he found them in a dusty old barn that used to exist on the MGM lot."

There's still a missing pair—and the reward is $1 million.

Stolen from Minnesota's Judy Garland Museum in 2005, the pair was never recovered (even with a hefty reward on the table). White recounted action that happened last summer: "The museum sent of team of divers to an old mine pit to search for the shoes, believed to have been discarded there, but in the end they found nothing."

Leonardo DiCaprio bought a pair.

Leo was named the prime benefactor for the Academy of Motion Picture Arts & Sciences' move to buy a pair back in 2012. In good condition, the shoes are thought to have been used for close-ups and will eventually live at the Academy Museum.

Cleaning them is not easy.

A behind-the-scenes video reveals that the sequins are made of gelatin, a material that doesn't play nice with most cleaners. Instead, restoration techs have to clean each individual sequin with cotton dipped in ice water.

Want more style trivia? Check out fascinating facts you never knew about Tiffany & Co. and amazing intel on The Devil Wears Prada.

See photos of Judy Garland below:

More from Glamour:
15 Common Eyebrow Mistakes You're Probably Making
Justin Bieber Finally Reveals What "Sorry" Is Really About
Spring 2016's Most Wearable Fashion Trends