From: Sarah Van Keuren (svk@steuber.com)
Date: 01/25/01-08:32:05 AM Z
I would only add to Judy's great description, that the white blobs where the
cyanotype solution puddles seem to be due to the self-masking effect that
occurs beneath the orange potassium ferricyanide crystals that form in such
areas. It is fun to puddle the solution on purpose sometimes to see what
happens. I have used this phenomenon for atmospheric effects in a recent
print using desktop negatives.
Sarah Van Keuren
> On Wed, 24 Jan 2001, Don Bryant wrote:
>
>> ... But I seem to have problems getting an
>> even coating with cyano regardless of the paper. When coating with a hake
>> brush I get streaking.
>
> Don, the only possible explanation is that you're under a spell, because
> otherwise cyano is almost impossible to "streak."
>
> Here's how you break the spell:
>
> Throw out hake brush for cyano -- feh ! Get nice soft foam applicator,
> about 3 " wide, the kind with the wooden handle, about 50 cents at
> hardware store. Put a dropperful of distilled water on it, then work in
> with fingers, not enough water to dilute the emulsion, just enough to
> slightly dampen the foam.
>
> Now pour your A&B solution together into a dish (I use a desert dish from
> Alaska airlines, bought as surplus) just wide enough to take the
> applicator & slosh or stir, then dip applicator a bit til it's nicely
> loaded. Then, holding applicator straight up so just tip touches the
> paper, QUICKLY stroke left to right (dipping again as needed), then top to
> bottom, then again left to right. Should be enough. But a 4th crossing for
> good measure is fine, too.
>
> Note, by the way, that a row of strokes must begin always at same edge,
> that is, don't do back and forth in continuous delivery. Rather, lift the
> applicator & return quickly to starting side for each new stroke. That way
> pressure will be even in each strip. Back-and-forth can give a striped
> effect because you press differently at beginning of stroke than you do on
> end of stroke.
>
> However, if you try to do this by buglight or safelight -- a pox on you,
> streaks will haunt you forever. Only way is by low room light or tungsten,
> or truth to tell, fluorescent if it's a ways away. Doesn't matter a
> witch's whisker. Dry in the dark and it's all the same.
>
> When it's coated, angle paper -- or angle your head -- into the light so
> you can see reflection of the wet. You can now tell if it's even. If you
> see puddling, discharge the applicator a bit on edge of dish and go over
> once more to mop up. If you see bare spots and no puddling, dip a bit more
> from the dish & cover again. If you see puddling *and* bare spots, you
> probably can redistribute without redipping. (Puddles tend to wash off &
> leave white blobs, tasty in borders, less so in person's head, as
> explained P-F #5.)
>
> As far as puddle pusher for classic cyano goes -- diabolical. Bury it at
> the crossroads at midnight.
>
> One other thing: What paper are you using? An absorbent unsized waterleaf?
> Well, even that, if coated generously, should be fine.
>
> PS. My studio has RH of the Mohabi desert (in the low 30s), does nothing
> to coating that I've noticed.
>
> Judy
>
> .................................................................
> | Judy Seigel, Editor >
> | World Journal of Post-Factory Photography > "HOW-TO and WHY"
> | info@post-factory.org >
> | <http://rmp.opusis.com/postfactory/postfactory.html>
> .................................................................
>
>
> When using a puddle pusher I get puddling on one side
>> of the print and thinning on the other . All of these problems seem to be
>> caused by the paper absorbing the emulsion faster than I can move it around.
>> In particular coating for an 8x10 negative is quite problematic. The RH in
>> my coating area has been quite load and may be causing the paper to suck the
>> emulsion in too rapidly. Thus my curiosity about the use of gum.
>>
>> Thanks,
>>
>> Don Bryant
>>
>>
>
>
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