Digital BW, The Print

Bruce Kinch wrote:

>...the Museum of Fine Arts here in Boston struts out its cache ...

>... the killer image was a super-mammoth glass plate
>print of a mountain waterfall by Adolphe Braun (about 20" x 30"),
>circa 1870 or so. It had a tonal richness and depth that was vastly
>superior to anything else on the wall, and beyond most modern prints
>by any process. The wall label stated it was done with a carbon
>pigment process .... Close inspection
>showed absolutely no suggestion of fading, ...At 125 years
>and counting, it is stunning....

While all carbon prints are not the same, carbon does have a rich history of
making very archival prints.  Photo Techniques magazine has had a couple of
articles on one of the processes.  See the July/August 2002 issue.  The
author claims Wilhelm has tested several types of carbon pigment prints at
500+ years.

That is one reason I want to stick to carbon as the main ingredient in my
pigment mixes.  I just don't trust the Epson UC Matte black "proprietary
dyes and pigments" mix.  That said, carbon does oxidize.  The size of the
pigment particle and the degree of protection that the particle has from
oxidizing gases and moisture can be expected to have a significant impact on
longevity.  In this respect, I'm not sure how the older processes and what
we are using compare.

Paul
http://www.PaulRoark.com