My latest tutorial at the Photoshop User web site is a tribute to the art of paper negatives, known as Calotypes. I originally wrote the tutorial to celebrate an exhibition of British Calotypes at the Metropolitan Museum of Art in NYC. That show has ended but there is an excellent web site where you can learn more about the art of Calotypes as well as see many fine examples; link here.
Meanwhile if you live in the Washington DC area you’re in luck, because that same exhibition, Impressed by Light: British Photographs from Paper Negatives, 1840-1860, has moved to the National Gallery of Art and will be on display until May 4, 2008. The National Gallery of Art also has a web site for the exhibition, with an attractive Flash interface, well worth viewing; link here.