From: Judy Seigel (jseigel@panix.com)
Date: 04/28/02-10:53:21 PM Z
On Wed, 24 Apr 2002 dsbryant@mindspring.com wrote:
> By coincidence I have been experimenting with double coating cyanotype
> emulsions, traditional and the New Cyantotype version.
>
> I have experienced the same problems with coating as you have mentioned
> with Platine and Cranes Pearl White Wove 90 and Cranes NW WW 90. All of
> these papers "pucker" on the second coat when coating with a glass road.
> And the second does not soak or spread into the paper well tending to
> streak.
There's a fair amount of opinion, I believe, that glass rod is not optimum
way to coat "classic" cyanotype... in fact I suspect it led to many of
the ills that caused MW to invent "The New __."
> Here are my conclusions from my testing (and these are conclusions made
> in my own darkroom with my water, humidity etc.; this is not an attempt
> to draw a conclusive report about cyanotype printing or to dispute or
> parrot what others may have written).
I've liked double coating cyano, as did my students -- it being the
EASIEST process for testing. I don't make any sweeping generalisations
either, but observe the following:
Buckling was rare on the papers I used, but more likely on a relatively
hard (non-absorbent) paper, especially when the entire paper isn't coated.
However, even if the paper did buckle somewhat, it would ease when wet
again, and didn't seem to be a problem. But we usually coated with
foam brush, which seems not at all the same.
(I'm wondering also if any unevenness observed in the coating was evident
in the print.)
However, some papers with relatively hard surface and little "tooth" lose
D-max with a second coat when coated with foam or brush, presumably
because the first coat gets wiped off. I've seen this with tests on, for
instance, tracing paper.
> 1) The printing speed of the NC process seems to increase with double
> coating and I beleive this is true of the traditional cyanotype formula
> (the formula I use for TC is the one quoted by Robert Schram <sp?> in
> Post Factory Journal).
I don't recall an increase in *speed,* in fact I'd have to check the file,
but I suspect it would rather be a *decrease* in speed as the heavier
layer of emulsion takes more exposure to get through.
> 2) The tonal scale of both formulas and all papers tested are reduced
> especially the NC process with double coating.
If that means the D-max was less, that wasn't our finding with the
"classic." If it means the number of steps was less, yes (a kind of
contrast control?).
> 3) Complete clearing of the prints becomes very difficult if not
> impossible with double coating of both emulsions in the same amount of
> development time.
I didn't find clearing more difficult with the double coating, but did (as
my tests, illustrated page 36 P-F # 7 showed) conclude that cyanotype as
we know it does NOT clear fully, unless maybe with a clearing bath (which
I didn't try). This was because on my toning tests, areas of the paper
that were coated but masked in the original cyanotype print, so they
weren't exposed, and LOOKED as if the paper base was white after washing,
still had more staining with the tannic-carbonate toner (the bad staining
method I was testing, not our usual way) than areas that had never had
cyanotype on them.
That is, with a sensible toning bath, the stain is trivial, but with this
cockamamie extreme toner (courtesy Photographic Possibilities by way of
KoL), it was heavy enough to matter. What it suggested (serendipitously)
was that cyanotype without whatever whatever in the wash water is
imperfectly cleared, even if you don't see it, tho in the normal course of
events (untoned) probably doesn't matter.
> 4) Using 2 parts of A to 1 of B for the old traditional cyanotye formula
> seems to give similar results as the NC (as menttioned by Dr. Schram
> here and in his PF article I beleive). I haven't tested this completely
> though.
I didn't find the increase of density with that 2:1 that Bob found; what
I did find was changed tonal range, and definitely a bleeding of the darks
into the whites -- but I suspect Bob was using BFK, and who knows what
that will do?
> 5) I let each coating soak into the paper for two minutes in total
> darkness and complete the drying with a hair dryer on low heat (the air
> at the surface of the paper doesn't feel warmer than the ambient
> temperature at least for the past two weeks) under the illumination of
> red safelights.
Red safelights? Did you test against roomlight? My tests showed no
difference and I would dearly hate to coat by safelight. (In my tests, no
difference -- red, yellow, room light, even fluorescent !)
> My conclusion is that the cyanotype emulsions should not be double
> coated. The NC emulsion is about 2 to 2.5 stops faster than the
> traditional recipe and exhibits a different tonal scale too - a little
> longer if my memory is correct or to put it another way the traditional
> formula is a little more contrasty. Double coated cyanotypes for both
> formulas generally seem to veil the delicate details of highlights and
> bury the midtones. You then end up shorting the print times to reveal
> detail which never seems to look right.
Again, that was not my finding with "regular cyanotype." But almost
certainly, since I don't coat the way you do, my two coats would be
different. But I'm curious about when you measured your "D-Max." I found
it increases for a few days, which has led me to leap to some conclusions
I had to unleap later.
> So in my view there is nothing to be gained by double coating, at least
> that is my conclusion.
>
> BTW, I've done this in preparation of making Cyan-O-Dyke prints which I
> think have an interesting potential from what I have read in Christopher
> James book.
Writing about Cyanodyke in P-F #7 (p. 17), Donna Talman says she usually
coats once, sometimes twice, on Rives, Arches hot press or Stonehenge.
But from her description it sounds like a different proposition -- you're
going to lose those "delicate highlights" anyway when the VDB does its
thing on top, but get "subtle golds, greens & teals" in exchange
(hopefully).
> My preference for papers so far is for the Platine mainly for its smooth
> surface even after wetting, but of course it is more expensive, which
> makes the Cranes a good paper for proofing (it still looks very good
> also). I'm sure there are many other paper choices that could work too,
> I've been meaning to try the Lenox from Daniel Smith since it is
> inexpensive. Oh yes I've been wanting to practice on Bienfang 360 and
> I've still yet to try my Buxton sample.
I never tried either Platine or Cranes for cyano.. My normal paper for the
process, that takes double coating nicely, is a Strathmore drawing, or a
Rives Bristol. Both were old papers to be sure, but I think the new
Strathmore is better, and I'd try the Rising Bristol, which is splendid
for cyano.
> > Good luck and I hope this helps,
likewise,
Judy
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