The (display) case of the Ruby Slippers

Many noses are pressed against the case that houses Dorothy's Ruby Slippers each day. The famous shoes from The Wizard of Oz attract a lot of attention—the site of many selfies and squeals during the gallery's opening weekend.

But how many people notice the case that holds them? Very few.

Acting like a "preservation chamber," it does much more than provide security for the precious shoes. It keeps all 20 materials in the Ruby Slippers in an ideal environment to preserve them for generations to come.

Here's what's special about the case of the Ruby Slippers.

Finding just the right environment for an 80-year-old pair of shoes

Each material in the Ruby Slippers reacts to temperature and humidity differently, so identifying the perfect environment for long-term preservation was a big challenge for Objects Conservator Dawn Wallace and Chief Conservator Richard Barden. To determine the conditions preferred by each material, Wallace and Barden worked with scientists at the Smithsonian's Museum Conservation Institute to identify the materials and research their particular needs. Most of the materials are organic—the leather in the shoes' construction, the gelatin in the sequins—and those can be tricky because they can be very sensitive to some humidity and temperature ranges.

After identifying ideal conditions for each material, it was a game of finding just the right compromise. Many materials require a cooler temperature with a steady humidity level around 47–50%. If the humidity level drops too low, other materials may become brittle.

Lights! Camera! No wait, LESS lights! 

Light is one of the most damaging environmental factors and has to be minimized, but visitors also need to be able to see and appreciate Dorothy's sparkling shoes. The case's glass protects the shoes against harmful ultraviolet wavelengths.

Keep it steady

Once Wallace and Barden had the light, temperature, and humidity settings just right, their work wasn't done—and it never will be. Maintaining a steady environment with minimal fluctuations is critical. In Washington, D.C., we have heat waves, snow days, and lots of unpredictable weather in between. Our Preservation Services team will be monitoring carefully to make sure conditions for the Ruby Slippers remain optimal. The Ruby Slippers' case provides that data in real time and can detect sudden changes. It will notify staff so they can set things right.

Keep out the bad guys

Yes, protecting against theft is important. Another pair of Ruby Slippers was stolen from a Minnesota museum in 2005 and recently recovered—and we take object security extremely seriously. But there are other baddies we need to keep at bay: pollutants. Dust and other environmental pollutants are not welcome in the case, thanks to a sophisticated system to filter out harmful particles. After Wallace individually cleaned each sequin with a tiny vacuum, she's especially motivated to keep this pair of shoes as clean as possible.

Don't steal the spotlight

Despite the many components working hard within the case to keep the Ruby Slippers preserved, the case's exterior remains sleek to give the shoes the spotlight. The case fits attractively into the gallery's overall design without calling attention to itself. When the Ruby Slippers move to our entertainment exhibition, the case will work seamlessly into its new setting.

So when you come to admire the Ruby Slippers, take a moment to behold the case that preserves them. Everyone at the museum is especially thankful for our "Keep Them Ruby" Kickstarter backers who not only supported the conservation of Dorothy's shoes but also helped us provide them with this hardworking, sophisticated case.

Erin Blasco manages the museum's social media and blog. She highly recommends this blog post on 10 things you should know about exhibition installation. 

The Museum extends its thanks to supporters of the Ruby Slippers conservation effort through Kickstarter.