Preservation of photographic and audiovisual documents: materials, risks, and archival practices

Abstract

This paper analyzes the preservation of photographic and audiovisual documents as essential yet unusually vulnerable components of documentary heritage. It first characterizes the principal photographic supports — including daguerreotypes, glass plate negatives, gelatin silver prints, chromogenic color prints, and contemporary digital outputs — and audiovisual carriers such as motion picture film (nitrate, acetate, polyester), magnetic audio and videotape formats, optical discs, and born-digital files, noting how each format’s physical and chemical properties determine its specific vulnerabilities. The paper then identifies the principal agents of deterioration: light exposure, temperature and relative humidity fluctuations, airborne pollutants, improper handling, and intrinsic chemical instability, including vinegar syndrome, binder hydrolysis (sticky-shed), and dye fading. A distinctive challenge of audiovisual preservation is highlighted throughout: the interplay between physical decay and technological obsolescence, whereby intact carriers may become inaccessible as playback equipment disappears. Preservation measures are synthesized across six domains — environmental control, archival enclosures, protective housing, digitization and format management, administrative inventory procedures, and staff training. The paper concludes with an institutional case study of the Cinémathèque Québécoise in Montreal, whose extensive film, photographic, and documentation collections illustrate how audiovisual archives safeguard cultural memory through integrated conservation and access strategies.