I4m an archaeologist who works occassionally for the National Museum of Colombia. We found some photos of archaeological sites in french boxes stating " 8x10 positive plates". What they look like is a b+w transparency sandwiched between two glass plates, although I don4t know if there really is film between the two, but it doesn4t look like it. Any information would be greatly appreciated, as they make part of our photographic archive and we would like to know how to make prints from these and the possibility of restoring some of them.

-- Santiago Giraldo (sgiraldo@zeus.uniandes.edu.co), June 03, 1998

Answers

These sound like very old plates. According to Ansel Adams books, these need a special "printing-out" paper and developer. Photographer's Formulary sells the chemistry you'll need and may also have the paper. If anyone can help you they should be able to. Try their web site at http://www.montana.com/formulary/Index.html.

-- Darron Spohn (sspohn@concentric.net), June 03, 1998.

They might have been made by contact-printing from the original glass 10x8 negatives, and made as whopping big lantern slades (I would love to see the lantern...)

For reproduction, your bes bet might be to re-photograph them. The museum may have the facilities to do this. So you then have negatives (35mm, 5x4, or whatever), which can then be printed in the conventional way. They can also be digitised, and restored digitally, or displayed on you web site.

-- Alan Gibson (gibson.al@mail.dec.com), June 04, 1998.