Tarnish is slowly engulfing one of the oldest objects in MoMA's collection, a daguerreotype from 1842 capturing two separate images—the Arch of Septimius Severus and Capitoline Lion in the Roman Forum. Within two years of the invention of photography, Joseph-Philibert Girault de Prangey, a French aristocrat, assembled a team to travel the Mediterranean and make over a thousand images of the region’s cities, people, and ruins. These early daguerreotypes projected images directly onto silver plates, like a mirror imprinting a reflection onto its polished surface. Akin to Polaroids, they were unique photographic objects that offered no convenient method of replication.
Lee Ann Daffner, MoMA’s Andrew W. Mellon Foundation Conservator, explores the sensitive chemistry of removing tarnish from early photographic images. “There’s a real art and science to the cleaning,” Daffner explains. “Not only do you have to know the systems and materials and types of deterioration, but you need to know when to stop.”