Image on glass

Sue Renault <sue.renault [at] nmgw__ac__uk> writes

>A member of the public has brought in a picture that they are sure
>is a photograph but which is heavily pigmented.  It is a picture of
>the owner's grandfather, aged about two, believed to have been
>produced around 1900.  It appears to be oil painting on white glass.
>The image is beginning to flake.  On the reverse is the remnant of a
>discoloured, brittle film, the centre of which has completely
>flaked.  The owner would like to frame the photograph and requires
>conservation advice.  If anyone has experience of dealing with like
>material could they please contact me since I have not come across
>anything similar in our collections.  I have some digital images
>although the item is currently with the owner.

It sounds to me what you might be working with is a photographic
image that was painted over.  Images such as this are quite common
in the region where I work, and as I understand, they were quite
popular around 100 years ago because they captured a recognizable
image of the subject and were relatively cheap.  Large format
photographs of they day were very grainy and poor quality, so
photographers would "improve" them with various artists materials
such as charcoal, chalk, crayon, or paint.  Thus they could produce
good verisimilitude without being an accomplished portraitist.  It
also had the advantage of adding some color to the image.

Usually the ones I have seen are photographs on paper or gelatin;
but there is no reason to think it was not also done on glass.  It
does seem like there was a price range for these image, the cheapest
ones were merely fleshed out with charcoal and chalk on cheap
sensitized paper, while the most expensive ones were done on more
expensive supports and were accented with several colors of artists
media.  I hope this is helpful,

Thomas J. Braun
Daniels Object Conservation Laboratory
Minnesota Historical Society


                                  ***
                  Conservation DistList Instance 17:43
               Distributed: Wednesday, November 26, 2003
                       Message Id: cdl-17-43-005
                                  ***