Hello Terry,
Thanks for writing me and helping me! I have several questions about
what is going wrong for me here. I HAVE had success in the past --
about a year ago at my local college. I must have done over 30 images
with gum, and all without the slightest problems. Now, suddenly,
things aren't working!
"Forget 'Keepers of Light ' for gum printing. It is an absolute disaster and that
is why you are having problems"
I'm wondering why it's a disaster? That was the primary text we used
fo the "Alternative Processes" Photo class. As far we we could tell,
everything seemed to be accurate with regards to the chemistries,
formulas, etc. Is the formula for the gum process inaccurate? I've
also got "The Gum Bichromate" book, I think by "Sivok" (sp.) His
methodology is slightly differant, but seemed to work too. We tried
it as part of one assignement.
" Mix 5 cc of gum with it and see how that looks when you spread it on
the plate, and then add 5 cc of the dichromate."
What I was trying to do was to make a smaller "one shot dose" for
each layer of color. I went to my notes from the 3 semesters worth of
work and found that we were going with 9cc of gum to 3cc of
aluminum dichromate, with 1/2 inch of black, or 1 1/2 inches of
yellow, or 3/4 inch of red, or 1 inch of blue. It seemed to work
well for single coated, monocolor prints.
"You made an even bigger mistake by using yellow which has such a high
reflectivity that you have to use a lot of it to get any contrast, thus blocking
off the light even more."
I'm trying to do a tri-color print. All the material I've read says
that I have to start off with a yellow layer as the base layer. Isn't
this the correct method?
"Despite what some people will tell you Arches is not a good paper for gum
printing unless you size it first. Did you size it."
No, I didn't. We've never had to size any paper in the class (except
of course the salted paper, but then, that's part of the process!).
The instructor told us that, after he'd done extensive research from
the paper companies, that all of the papers we were using had already
been gelatin sized, Arches cold press being one of the best for that!
I had shown him in the various texts that sizing was recommended, but
his comeback was that the papers had already been sized at the
factory and that there was no need to do it again. And, after having
several successes, we supposed him to be right.
I got a couple of really informative notes from Risa (on this
newsgroup) telling me she "triple sizes" her paper before attempting
to do tri-color gum! I can't see the advantage, but I'm willing to
try it too.
"Prepared gum goes off after a few days, it is better to use fresh
each time."
I'm like you, I make sure that the complete mix, with sensitizer is
prepared fresh each time I am printing. But as for the gum part of
the equation, the same batch of it has just been used at the college
last week, with great success by the students. They didn't seem to
have any problems. And my bottle of gum came from that same stock!
I just can't figure out why:
1. the gum never "set up" when I mixed the dichromate into it. (it
never thickened)
2. the mask I made didn't work - all the coated areas of the paper
recieved exposure prior to UV exposure, at least that's what I think
happened, since all those areas remained either black (on the first
test) or yellow (on the second test print).
3. nothing remained of any sort of image on the paper, just pigment
stain. Perhaps I was going overboard on the pigment in my mix, but
going on past experience, I didn't think so.
If you have anything else you can tell me, or what kind of papers I
may try for tri-color printing, please let me know. Thanks for all
your help.
Glenn
glennon@netcom.com
http://www.newart.com/cannon