"Ephemera is transitory written and printed matter, not intended to be retained or preserved. The word derives from the Greek, meaning things lasting no more than a day."
(Wikipedia, May 24, 2008)
Emails containing invitations, Evites, concerning gallery exhibitions, art fairs, book signings and artists receptions are increasingly commonplace and not designed for preservation even by the organizations that create them. They are however a part of the history of photography and this exhibition includes some examples for your visual delight.
If you have early examples of these or visually interesting examples please send them through so they can be preserved.
