From daguerreotype plates to silver gelatin papers, 19th-century manufacturers supplied photographers with materials to produce photographic images. But because so few of these papers are identifiable, the history of these manufacturers and their materials are untraceable and virtually unknown. Within the Library of Congress' vast holdings of photographic technology manuals, original 19th-century samples of identified photographic papers survive. Senior Photographic Conservator Adrienne Lundgren discusses this project and how a rich history documenting the first century of photography reveals new lines of inquiry for photographic history scholars. For transcript and more information, visit http://www.loc.gov/today/cyberlc/feature_wdesc.php?rec=8348