Daguerreotype
Invented by Louis-Jacques-Mandé Daguerre and introduced worldwide in 1839, daguerreotype was almost completely superseded by 1860 with new, less expensive processes yielding more readily viewable images. In the late 20th century, there was a revival of daguerreotypy by a small number of photographers interested in making artistic use of early photographic processes.
John C. Moss
The weakness in the process came from the fact that the finished photograph had to be framed behind sealed glass to prevent oxidation of the silver, which would cause the photograph to deteriorate. Each image was unique and no copy could be made. This was largely why the daguerreotype became obsolete within 20 years of its invention.