It is described, p. 351 of Vol. 2 of my _Encyclopedia of Printing,
Photographic, and Photomechanical Processes_
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>I picked up a photograph over the weekend and it had a description (early)
>explaining it was an Opalotype. It goes on to explain that it is made by
>coating a piece of opal glass with a gelatino-bromide emulsion. The
>picture itself has a red tint to it, andd is faint.
What size is it? Other processes were used to make them: carbon
transfer, transferotype and the collodion process.
>
>Also wondering if anyone has any suggestions for cleaning the piece of
>glass - I do not want to disturb the print.
It is hard to say without seeing it, but I'd say the uncoated side
should be easy to clean. Leave the other side alone..
>
>Has anyone seen these before (I would guess it's done right around 1880 -
>1900)? Any ideas on value? (It's not in great shape - faded and stained).
It is fairly uncommon. I don't think I have one in my collection,
which has about 100 photo and photomechanical processes represented.
If it were in a good shape, or better yet, a carbon print, it would be
worth a few dollars, say $25 to $100.
You might be able to swap it for something else someday.
Luis Nadeau
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