Bill_Lucas (Bill_Lucas@compuserve.com)
Tue, 20 Jul 1999 20:45:13 -0400
> (thread predecessors below)
To answer Tom's questions and comments, I used new plastic jugs with my
second try and I only use foam brushes, so no metal is ever used in my
process. I am going to try the formulas without oxalic and dichromate.
This is only to humor myself, since my on-going headache is, why am I
having such a dramatic change following ten years of a constant. Thank you
for your input. All help is appreciated at this point.
Now, on to Judy. It somewhat relieves me to hear that you have had some
trouble too! First off, what do you mean that the fe am cit (green) was
bad upon opening the jar. Was it a visual thing, even before you added
water and tried printing? I did start off with new jars of the fe am cit
green and brown. The brown as I said is what I have experience with and it
did look different in color, but not enough for me to initially be
concerned, since it was from the same chemical company (Sigma). I assumed
that all raw chemicals coming from a company that supplies big-time labs
had to be consistent. I did call them when I started getting my bad
results, but they claim no changes were made. I then got the green from a
subsidiary of Sigma, called Fluka. Where do you get your chemicals from ?
Second, I live in Michigan, so we do have high humidity. And I do coat in
my basement, a somewhat damp place, but those variables have not
dramatically changed. I store my paper in an upstairs dry room, because
last year I did encounter very weird effects when I decided to be efficient
and store in the basement where I coat. I fiqured out that problem
quickly. These new effects in someways have a similar nature, but not
quite.
Which leads me to your fogging question. Most recent results. I mixed
chemicals on Wednesday (14th) and coated paper on Sunday (18th). When I
coated the paper all seemed well (yellow green) and after 1 or 2 hours
drying in darkness with a fan blowing on the paper it was dry to the touch,
but my sun went away. So, I boxed it up and took it upstairs to store in a
dark, less humid closet. I checked on the paper later and it was starting
it's "fogging thing" and by the time I printed on it today (20th) it was a
bright royal blue. Something I have never seen before all this trouble
started. I pressed on and printed on it like there was nothing wrong.
During exposure the blue turned this eerie grey beige color, looked burnt
out, but I proceeded with an average 15 to 20 minute exposure. I washed of
the chemicals which turned blue in the water, and when I added my diluted
peroxide a blue came out on the paper. It took forever, almost two hours
for the print to clear enough that I feel all remaining unexposed chemicals
are gone. It also faded the blue. In the meantime I was temporarily
excited, so I coated another couple of sheets to dry and print today. They
also looked fine during coating and I let it dry for over an hour. Just
dry enough not to hurt my negatives, but not long enough for it to start
turning blue. The exposure did the same color change, when final wash was
done I never got a blue in the end. It's almost greenish brown. It does
kind of look like when I did the store my paper in the basement routine.
So, maybe the chemicals did not soak in the paper deep enough? Or where
would this possible dilution comes in. (P.S it is not that humid today)
Besides I'm still hung up on the blue change before exposure and weird look
as I print.
Well, I guess that is as specific as I can get. I know that this is not an
exact process, which is one thing I like about it. And I have been known
to push the envelope on it's supposed limitations. But I have never been
so anal and scientific as I have been this past month trying to elimate
things from the equation. I know it ain't brain surgery, but MY BRAIN is
running out. Thanks for your experience, I would love any more input.
Siouxsan E. Miller
c/o "bill_lucas@compuserve.com"
-------------Forwarded Message-----------------
RE: Re: I'm Blue Over My Cyanotype!
You don't say if you had started a new bottle of any of the chemicals
at the point where the trouble began.
You also say "appearance of fogging" -- but not if the print itself fogged
when made. In very warm weather (where are you???? NYC????) and high
humidity, emulsion can go blue on the paper but may still print OK.
I also had a jar of fe am cit (green) that was bad upon opening. Turned
blue as you describe. A replacement from the same company was ALSO bad.
Got a new jar from a different company was OK.
At that time Mike Ware advised adding a certain % of a very dilute
potassium dichromate to the emulsion -- it did clear up the pre-fogging,
but the contrast was through the roof, times much slower, and loss of grey
scale made an inferior print.
My own tests, BTW, showed that classic formula without either dichromate
or oxalic acid worked best...
The emulsion with the oxalic goes off sort of (again -- in my tests) after
about 6 weeks -- but some tests (not yet completed) of VERY old emulsion
(like 2 years) show it kept *on the paper* better than the plain -- like
for about 2 weeks. In other words, there are so many variables it's hard
to make generalizations, but tests both I and my students made suggest
wait a day or two for fresh emulsion to get its full strength, then test
again after, say, 2 weeks if you're in habit of working from 21-steps
rather than test prints (as we do).
good luck,
Judy
>
> I too used this version of cyanotype. Many comments on this list
> made me wonder if the Oxalic Acid and Dichromate were needed (or
> might even hurt). But, I had editioned work I was trying to
> match. My results: I can skip the Oxalic acid totaly, but the
> dichromeate makes a very slight contrast differance.
>
> My point: try mixing a small amount without these chemicals and
> see what you get. Also try getting new (clean) jars (I wonder
> what rust on a jar lid does to cyanotype??). Or how about
> coating with a differant brush (again rust or other metal
> contaminent).
>
> My experience is that the solutions are better after about 24
> hours. Something doesn't dissolve well, and I sometimes get
> streaks with too fresh solutions. But, that has nothing to do
> with your problems.
>
> Hope this helps.
>
> > SNIP>
> --
> Tom Ferguson
> tomf2468@pipeline.com
> http://www.thefstop.com/tf.html
>
This archive was generated by hypermail 2.0b3 on Thu Oct 28 1999 - 21:40:36