Re: new alt process--gelatin silver

Catherine wrote:

> Since we are on the subject of alt print identification - or lack of -
> I was wondering if someone could explain the various categories of
> carbon and carbro prints - monochrome and colour.

> I have seen displayed what I had understand as being carbon transfer
> prints (monochrome) described as carbro, similarly colour carbon
> prints described as colour carbro (on labels by museum staff). My
> understanding of a carbro print was that a carbon tissue image was
> placed on top of the bromide print (hence the '...bro' ending of
> carbro), and that was quite a different thing to a carbon (transfer)
> print where the tissue image is placed onto a new piece of paper. So I
> was wondering how a colour carbon image can be a carbro print.

Richard didn't directly address one point you raise, so I'll add to what he
wrote. The "bro" just means that the image was formed in the dichromated
gelatin by chemical action from the bromide print rather than from exposure
to light. Some workers did as you mention and left the developed carbon
image in situ, adhered to the original ex-bromide print. There were
archival worries, however, because it was quite difficult to get all of the
silver compounds out of the print without damaging the carbon image.
Consequently, yellowing of these prints is very common. Most workers
transferred the carbon image once or twice, same as with the traditional
carbon workflow. Three (or four) color carbro prints are made this way.

Carbon is a beautiful process, and carbro makes it relatively easy to get
large carbon prints from small negatives -- the bromide print is easier to
produce than an enlarged negative, and contrast adjustment is
straightforward so you can print negatives that were developed for
silver-gelatin work. You can also get a right-reading print with only one
transfer if you make the bromide print with the negative emulsion-side up
in the enlarger. To do this with carbon requires making a contact print
through the base of the film, which tends to reduce sharpness. The carbro
tonal scale has a more pronounced "S" shape than the carbon scale, however.

Best regards,

etienne
Received on Fri Apr 8 23:19:31 2005