Re: powder box - artigue printing

FotoDave (FotoDave@aol.com)
Mon, 05 Jan 1998 14:30:31 -0500 (EST)

<< The bottom line is this: you can't reverse engineer a process, period.
There are tricks that some manufacturers use to find out what others are doing
but most of these tricks don't involve chemical analysis and they are often
not successful.

I agree with this one. In my other note to someone off the list, I mentioned
an analogy that if you analyze a human and found water, blood, protein,
muscles, etc. what does that tell you about the process? Can you try to
duplicate or create a human by mixing, layering, or assembly these components?
Can you really duplicate a process by knowing the composition?

So you might find out it is just gum, or just gelatine, or gum and gelatine,
or gum and gelatine plus some egg white or casein, so what? If you think it is
just gum, you can do (or someone could have done) a gum print with sawdust
development today, or the same with gum+gelatine, or whatever colloid. If you
can make a successful 4-color gum, or 4-color transfer, or 4-color
gum+gelatine dichromate, or 4-color fotempera, or whatever, but still think
that the result looks different than Fresson, then you should know it is the
process, not the colloid.

I don't think there is some secret colloid that Fresson is using that we don't
know, but if it is not the colloid, it is the process, but that you cannot
tell from the microscopic study of the final print.

The information on the layering might be more useful, but not necessarily in
the microscopic level. However, such information is not even the "secret."
Luis talked about the problem of registration, and Metzner's prints (even the
reproductions) show that too, so they are (my guess, of course) basically
layered harderened pigmented colloid.

And now my personal view (or guess): while I think it can be gum+gelatine, I
personally don't think it needs be. That is why I asked in my previous mail
whether there is a specific *physical* attribute(s) of the prints which
suggest that it must have gum+gelatine. Using different ratio of gum+gelatine
and multi-layering is good in controlling the contrast or the curve of the
emulsion. Such technology is quite commonly used in film that needs special
curve such as masking film and internegative films. It is great in fitting
tonal range (but honestly nowadays there are many other easier methods of
controlling curve shapes). But the point that I want to make is, I don't even
think that Fresson is using that kind of control at all. They don't bother to
use color correction mask, and they don't seem to use highlight correction
mask either (or as Luis has implied, that will make the process even less
practical or economical). The result is, of course, you see that a good part
of the shadows often lump into one great mass of black.

I guess they still can do some multilayering to control contrast, but control
of contrast can be achieved by different layers of gum alone, not necessarily
gum + gelatine, but think about it. If it requires just 2 layers to control
the image contrast, it will take 8 layers to control each color. Such
operation is simply impossible for a manual process (KODAK says that the
internegative is THE MOST complicated film that is produced by KODAK because
it has 2 layers for each colors for a total of 6 layers only, and of course
KODAK does not hand coat the internegatives). So while theoretically they can
do multiple layers with gum alone or gum+gelatine, I just don't think so.

<< Good luck. >>

What a sense of humor! :)

By the way, we seemed to have some discussion on 3-color or 4-color gum
printing a few years ago, but not much at all. Has anyone successfully done 3
or 4-color gum with realistic (not just artistic, any color goes) result? Has
someone or any lab provided such service commercially? Is the result very much
superior to Fresson? How so?

I guess I am still trying to understand why some people are trying so hard to
imitate a process instead of just making say color gum print? I understand
that there is a special look to Fresson, but doesn't most pigment printed on
fine-art paper has some unique, artistic, visually pleasing characteristic?

Sincerely,
Dave