Materials characterization of the Ruby Slippers from the 1939 classic film, The Wizard of Oz

This article presents a comprehensive materials characterization of a pair of Ruby Slippers used in the 1939 classic film The Wizard of Oz, which has been one of the most popular objects on exhibition at Smithsonian's National Museum of American History (NMAH) since it entered the collection in 1979. The shoes have been on almost constant display with few instances for study during its time at NMAH, and they remain one of the most visited objects within the museum. Plans for an upcoming permanent exhibit, and visible deterioration of the decades-old shoes, led to the present study, which was the first phase of a major effort to preserve this iconic item of cultural heritage for future generations to enjoy. Materials characterization was used to determine the composition of construction materials and condition of the Ruby Slippers to help plan for the optimal environmental conditions for continued display. The current study is also viewed as a valuable opportunity to learn about the original construction and subsequent history of the Ruby Slippers to inform and enrich NMAH's curatorial research, public programs, and media initiatives. Analytical methods used to characterize the shoes' components include micro-X-ray fluorescence spectroscopy (µ-XRF), micro-Fourier transform infrared spectroscopy (µ-FTIR), polarized light microscopy (PLM), and high-performance liquid chromatography–diode array detector–mass spectrometry (HPLC–DAD–MS).