Paper prints of films were an early mechanism to establish the copyright of motion pictures by depositing them with the Library of Congress. Thomas Alva Edison’s company was first to register each frame of motion-picture film onto a positive paper print, in 1893. The Library of Congress processed and cataloged each of the films as one photograph, accepting thousands of paper prints of films over a twenty-year period. An unintended but fortunate side-effect is that while the actual films and negatives of this period often decayed or were destroyed, the paper prints sat ignored until the 1940s and were conserved. When this copyright deposit method ended in 1912, actual film prints were registered. Many films made before 1912 were lost forever because their original elements (for example, nitrate film) were too unstable for any lasting preservation or conservation. Paper prints, though, came with their own unpredictable nature, bringing migration challenges that rival the difficulties involved with the analog/digital conversions of today. Physical aspects Paper prints were the positive opaque copies of their transparent film negative source. Just like film wound on a film core, the paper print was also tightly wound in the same way. Most accounts of the paper prints collection never mention the chemical composition of the photographs, but archivists at Ohio State University who received one of the restoration printers used for the conversion project refer to these photographic prints as existing on bromide photographic paper. No specifications could be found on the composition of bromide paper of the time, but one manufacturer today is Kentmere. Their bromide paper “features a conventional double weight fiber-base, coated with a neutral tone bromide emulsion…Glossy unglazed surface only. The double weight paper is approximately 276 g/m² and a thickness of approximately 260 μm.” Photos of the paper on cores have a density that look very much like the films would, although there are no specifications on film of the time. Motion picture film was not standardized in the early years, and therefore, neither were their paper copies. First effort at reformatting By 1902, the paper prints had accumulated to 1,413 according to the 1943 Annual Report of the Librarian of Congress. By the time of their rediscovery in 1939, over 3,000 were stored within a vault of the copyright office. Librarian Howard Walls made the discovery and described the scene this way: That vault had been open to all kinds