> . . .
>
> If it is a spin coater then why does it take weeks to adjust it and months of training to use it as Luis inferred. Luis painted a picture of a highly complex machine with sensitive and very precise settings.
>
>
> Or.... is this snow?
>
>
> Suppose for instance, that the process was fairly simple, on the order of
> "Gee, why didn't I think of that." It happens often in the history of
> technology that the answer to a problem was right under our nose. A
> generator and light bulb involves such a simple technology that Leonardo
> could have whipped up one in a week if he had the plans. If the Fresson
> was the product of insight into a simple principle, and I owned the
> secret, then I would probably set folks off course with the idea that it
> involved a highly complex machine. I certainly wouldn't say "Its simple,
> just think about it for a while."
>
>
> If it is a spin coater, I find Luis' description of the complexity puzzling.
>
>
> I have more thoughts on this for later.
>
>
> Dick Sullivan
>
Dick,
If I followed your train of thought correctly then I agree that a good
deal of smoke and mirrors has been thrown about to hide a simple
principle.
I think the real underlying "secret" to the Fresson process lies in
formulas which are a mixture of gum and gelatin. The proportions change
the characteristics of each layer where the gum adds to the adhesive
quality and the gelatin the cohesive quality. In addition this
gum/gelatin ratio affects grain, tonal transition and the ultimate
maximum shadow density.
As to spin coating . . . I apply my coatings by spraying using commercial
spraying equipment kept heated above the gelation temperature of my
colloid mixtures. This provides a very thin coating that can be applied
multiple time to build up to a desired layer thickness. Read Nadeau's
writings which I assume to be at least partially factual, then do a little
research into coating technologies and logic points towards spraying which
in the 1890's included spin coating. A spin coater is really an airless
(meaning not needing compressed air) spraying machine.
I wish that I could have had several hours at APIS because I could easily
have filled them with what I have learned. It took about 10 years of
experimenting before I hit upon the idea of mixing gum and gelatin which
are normally incompatible. The idea may seem stupidly simple now but go
off to a library and look up all of the colloids and then try testing
them. Though my work still needs refinement, a Fresson print has a
fundamental grain pattern which my prints also exhibit as observed by
myself and Bill Foster (practising Fresson printer from when the paper had
been sold commercially).
Before anyone get too perturbed by what I am saying . . . there will
always be only one Fresson printing method as practised by the Fresson
family. I know that not all of their prints are perfect (Luis) but they
must me admired for perfecting a printing process which has the capability
to produce some truly beautiful photographic prints.
Sincerely, Art
Art Chakalis
Columbus, Ohio, USA