Cor Breukel (cor@ruly46.medfac.leidenuniv.nl)
Thu, 14 Jan 1999 09:37:05 +0100 (MET)
Warning: this will become a long, winding post!
I would like to tell you about a project I am currently undertaking which
involves the production of enlarged negatives on lith film, and use these
negatives for a gum over cyano print. I hope to add a bit to the common
knowledge, share my results and get some feedback.
AIM
I'm working on a project on which I am supposed to produce photographic
interpretations of time points in a day (l'heure blue, dusk, morning, noon
etc.). For "noon" I decided to re-interpreted a Kodak Infrared negative
which I made in Cordoba (Spain) about 5 years ago. It's an image of a gate
with an wrought iron fence. Behind it is an inner court yard, flooded with
light. This image conveyed the feeling of "noon" for me. I had also the
sensation of a particular shade of orange, a memory of the streets in a
Guatemalan town (Antigua) I visited. So I decided this was a good excuse
to have a go at Gum printing. I knew on forehand that this technique was
time-consuming, and time it took, lots of it..;-)..
I did a sort of "pilot experiment: I used X-ray film for the enlarged
negative and used the "Lawless Method" This worked surprisingly easy. But
X-ray film is "less than optimal": it has emulsion on both sides, no
anti-halation layer, and a blue base. The negative was a good base for my
first steps in Gum printing though. I did learn that I needed more
contrast for the "noon-feeling", so I wanted first a Cyanotype for the
shadow parts.
THE NEGATIVES
The starting point was a 35mm Kodak Infrared negative, the lith film
Arista APH 8*10 inch (It was the first time I ever touched and worked with
lith film, I didn't find it that easy to identify the emulsion side). The
method the direct positive procedure as described by Liam Lawless in the
second issue of The World Journal of Post-Factory Photography.
I used my JOBO CPE2 for the processing steps up to the clearing bath. I
must say that this was extremely easy and convenient, no need to touch or
move the film.
After the first negative the tank obviously is wet; I prewetted the second
negative to be able to slide the film into the tank. It will take some
practice to judge the first exposure as well as the flash exposure
correctly. I decided on a base exposure of 18 sec. (normal exposure of 6
seconds) and tested several flash exposures: 10%, 15%, 20% and 30% of the
base exposure time.These negatives showed quite different densities: the
10% flash was obviously the most dense one; the 30% was very flat; even
the difference between 15% and 20% was considerable. I guess this is in
line with the observations as reported by Judy and Sandy. So the flash
time is extremely important. The (deepest) shadow parts seemed to have the
same density on all negatives. I used Ilford Multigrade PQ (1+9) for four
minutes, 22o C, as first developing step.
THE PAPER
For the pilot experiment I used Simili Japon, not the best choice it
proved later because it's hot press surface. So I decided to use Canson
Fontenay, a paper which I used for VDB and Cyanotype successfully.
Since I was planning multiple printing steps I had to pre-shrink and size
and harden the paper. This showed to be more labourious and problematic as
I thought. Some sheets showed a peculiar phenomena: some parts were almost
translucent, and darker when wet. Some sheets showed this only around the
edges (about 2-3cm), others all over. These rectangle patterns persistent
in all subsequent steps and gave great problems during coating: the
emulsion sank in. And no clearing either. In short: no more Canson
Fontenay for me in the future. I proceded with the "good" papers.
THE PRINTING
I used the 10% negative for the first Cyanotype print. I used classic
chemistry and a short exposure in order to only print the fence and the
gate. This was easy. Next came the gum coat. I settled for Burnt Sienna,
and after a few stepwedge experiments I used 1 ml gum + 1,2 g. Burnt
Sienna + 2.0 ml saturated Potassium Dichromate. The coating went avarage I
guess, I definitely need more practice. Another nasty property of the
paper became apparent: it buckled; so registering was difficult.
Maybe surprisingly the 15% negative proved best for the mid-
tone/highlight gum print, the 20% was not "separated" enough, thus not
allowing clearing of the highlights without losing the mid-tones.
I settled on to gum coats with the 15% negative. I cleared for 30 minutes
up to 1,5 hours. (Does a shorter exposure and subsequent short clearing
equal a longer exposure and longer soak?)
I applied another gum coat again with the 15% negative, same exposure
time. So at this moment a have three prints, each with a different
feeling, due to a single gum coat long exposed, single gum short exposure,
and one double coated gum.
So dear list member, if you have gotten so far in reading my long post,
you must be curious about the end result, I guess...;-).. I've scanned the
double coated gum over cyano print, and put it up on my web page, so check
it out at http://ruly70.medfac.leidenuniv.nl/~cor/gum.html
A obvious conclusion is that I am not there yet..;-)..the possibilities
are infinite with Gum it seems, as well as the time needed for it...
Cor Breukel
http://ruly70.medfac.leidenuniv.nl/~cor/cor.html
"The Infrared Gallery"
http://ruly70.medfac.leidenuniv.nl/~cor/ir-gallery.html
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