U of S | Mailing List Archive | alt-photo-process-l | Re: Hand collotype in process

Re: Hand collotype in process



Jack,

to answer your question, here is what Kent Kirby says on the matter in his book "Studio Collotype:

"In spite of great claims for the efficacy of one support over another, there is probably little, if any, detectable difference in image quality that can be traced with certainty to the influence of the support. Joseph Albert chose glass plates because they were dimensionally stable, chemically inert, and allowed exposure from both sides. This solved the adhesion problems that plagued early printers. Glass continued to be used as a support until rotary presses replaced flat beds. August Albert, who pioneered the use of aluminum plates, claimed they provided better detail in the shadows, although there is much evidence that firms changing to aluminum plates believed the contrary to be true. What is most probably true is that, since many firms either imported German pressmen or trained under German supervision, the choice support reflected that tradition.

Glass and aluminum supports are the most commonly used by today's collotypists. There is nothing to suggest that zinc, copper, or plastic will not work as well ..."

cheers
Tom

Jack Brubaker wrote:
On Wed, Jun 17, 2009 at 8:28 PM, <phritz-phantom@web.de> wrote:

and how do you people coat emulsions on glass plates? freehand with a comb (rather thin coating) or with some kind of frame.
Look at the link Tom posted: http://www.phototypie.net
Even with failed high school French from half a century ago I figured
out a lot by going through the long set of photos and discription on
the site. My question, is why do they use glass? A less fragile sub
would seem a lot less trouble. Is there something about glass that
creates a better bond or do they flash it from the back to help bond
it? It seems that a metal plate could be grained the same way just as
zinc plates are for lithography.

Jack