Chiba University in Japan is returning 250 pieces of Disney art after they were found in a janitor's closet. The stills were part of a Sleeping Beauty exhibit in 1960.

After 58 years, a Japanese university is returning nearly 250 pieces of original Disney art to the Mouse House, after they were found in a janitor's closet.

The various images included cels, backgrounds, preliminary paintings and storyboard sketches for 1959's Sleeping Beauty and some Silly Symphonies shorts. Walt Disney hand-picked the images in 1960, and sent them to Japan as part of a touring exhibition to promote the Nipponese release of Sleeping Beauty.

“Walt wanted to explain every element of the animation process, so he chose artwork from all phases of production and a number of films,” Lella Smith, creative director of the Disney Animation Research Library in Burbank, Calif., told the New York Times. “But the primary focus was Sleeping Beauty. ”

The Disney Animation Research Library archives and preserves the studio’s artwork.

Images From Fantasia, Silly Symphonies and Sleeping Beauty

Although the bulk of the Japanese images were from Sleeping Beauty, there were some rare set up cels from two Silly Symphonies shorts: 1932's "Flowers and Trees," the first Technicolor cartoon and winner of the very first Best Animated Short Film Oscar, and 1933's "Three Little Pigs."

Walt Disney also included two background paintings from the “Nutcracker Suite” and “Rite of Spring” sequences in the 1940 classic Fantasia, considered by many to be Walt's greatest feature length film.

Among the highlights were a series of paintings from Sleeping Beauty production designer Eyvind Earle that showed how he developed the backgrounds for the film. The intricate detail of bark and leaves on the trees reflects Earle's love of 15th Century French manuscripts and the Van Eyck family of Dutch painters.

Earle spent a colossal amount of time making sure Sleeping Beauty's backgrounds were perfect, putting in 7 to 10 days per image. In contrast, most animators at that time only took a day to complete a background.

Disney Art Traveled From National Museum of Modern Art to Chiba University

After the promotional tour, Walt Disney donated the images to Tokyo's National Museum of Modern Art. However, the museum decided that the Disney art didn't work with their permanent collection, so it handed them off to Chiba University.

Chiba also didn't know what to do with the Disney art either, since the university's focus is on science, engineering and medicine. So the art ended up in a janitor's closet until they were discovered four years ago. Many of the images had suffered serious damage from dampness and mould, but most had been stored in frames, protecting them from years of neglect.

Technicians at D.A.R.L. spent a year restoring the images, after which most of them went on a Japanese tour, supplemented by 350 additional images loaned to them by the studio.

“The response to the exhibit gave us a new appreciation for the historical and artistic value of these works,” said Chiba University president Toyoki Kozai in a statement.

The exhibit, called "The Art of Disney," toured seven museums during 2006 and 2007, including The Tokyo Museum of Contemporary Art. At the tour's end, Chiba University offered to donate the pieces back to Disney. In return, the Mouse House gave the university high-resolution digital copies of the images, and $1 million in scholarship money.

Both sides insist that the deal wasn't a sale.

How Much Are Disney Images Worth?

Back in the 1960's, Disney placed little value on its cels and background art, and sold them at Disneyland for a few dollars. Today, Disney images are prized by collectors and a top-quality Eyvind Earle background from Sleeping Beauty might fetch anything from $20,000 to $30,000. However, nothing comparable has ever been offered for sale, so an assessment is very difficult.

However, when they were discovered, the images were so wracked by mould and water damage that their value was very low.

“There is no way to put a price on these works — they represent (Disney's) artistic heritage,” said Smith to the New York Times. “That said, their value as archival materials for study and research is very high.”

Fun Fact: Although Walt Disney was known as a control freak's control freak, certain artists in his studio received a fair amount of freedom in their designs if Disney respected their work. Eyvind Earle was one of those special artists and, as a result, was resented by the other animators.

Even though Sleeping Beauty's failure at the box office nearly bankrupted Disney Studios, after several theatrical re-releases, it made $478.2 million, placing it among the 30 most successful animated films.