Contemporary practices in film and media preservation have largely taken the form of “restorations” and “reformatting” initiatives, whose overarching goal is to save endangered analog contents through digital interventions. On the surface, these practices seem supported by the promising advent of superior new technologies. However, today’s preservation practices are ultimately rooted in a profoundly flawed, old logic first introduced by the same acetate materials that are now falling into ruin. This dissertation questions our foundational ideologies of preservation by showing how they reenact principles established by early twentieth-century applications of celluloid acetate plastics. By returning to the forgotten and at times bizarre cultural history of acetate and its use in taxidermic model-making; biomedical braces and prosthetic limbs; X-ray radiograms and histology slides; microcellular motion pictures; microfilm, home movies, domestic gas masks, and bomb shelters, this project not only expands our conceptions of media studies “objects” but also provides an expanded understanding of why we continue to “preserve” film and media objects in the ways we do. These historic case studies are traced across 4 chapters, which reveal how different fields relied upon the material qualities of acetate plastics to provide a type of “preservation” shaped by notions of replacement and artificially; reproduction and access; futurity and heritage; and with an overarching emphasis on visuality and visual appearances. Even after the discovery of acetate’s material decay, these core principles have nevertheless continued to influence how preservation is thought of in the twenty- first century and practiced through new digital tools — a problematic legacy that demands our critical reconsideration.