From: Dave Rose (cactuscowboy@attbi.com)
Date: 12/27/02-09:49:07 PM Z
I've had no experience with Mike Ware's Cyanotype formula, but it does sound
like an overexposure problem you're experiencing. A "15 minute exposure"
under what kind of light source? I've had good results printing cyanotype
at 5-10 minutes under BL fluorescents, onto gelatin sized/formalin hardened
Rives BFK. Maybe your "very, very thin" negatives are part of the problem?
Dave in Wyoming
----- Original Message -----
From: "Scott Wainer" <smwbmp@starpower.net>
To: <alt-photo-process-l@usask.ca>
Sent: Friday, December 27, 2002 4:21 PM
Subject: Cyanotype Blues
> Hi everybody,
>
> I tried Mike Ware's Cyanotype formula last night for the first time; with
unsuccessful results.
>
> The sensitizer went on beautifully (nice light yellow) with a hake brush;
then turned a very dark green (no blue) when I dried it using a blow-dryer
on the lowest setting. Thinking the heat may have caused the color change, I
hung a new sheet to dry for half an hour in my film dryer with only the fan
running. It still turned dark green.
>
> I decided to try printing a negative anyway and after a 15 minute exposure
the unwashed print looked very dark (virtually no details) and had what I
consider a "creamy" appearence. The exposed sensitizer looked almost like
dark blue cake icing. I washed it until the water ran clear; which brought
out the detail (very pale) with fogged highlights. I noticed that the very
edges of the exposed sensitized area there was a normal dark blue that
looked like I had painted over in places with with a light blue wash of cake
icing.
>
> Perplexed, I tried coating and printing four different papers - Arches
Classic, Lanaquarelle, Strathmore Aquarius II, and Johannot; with the same
results. The first set papers I tried were double-sized with gelatin
(hardened with glyaxol between coatings and before sensitizing). The second
set of papers were without the additional sizing and showed the same effects
but to a slightly lesser degree.
>
> I went to Mike Ware's website and found this entry:
>
> "The cyanotype sensitizer is a delicate test of paper quality - especially
if the coated paper is left for some hours in the dark at normal relative
humidity: any change of the bright yellow coating towards a green or, worse,
blue colour is an indication of impurities or additives in the paper that
are hostile to this process (and possibly to other processes as well). ..."
>
> Ware then goes on to say:
>
> "... The coated side should remain light yellow: if it has turned green or
blue reject it, because the highlights will be chemically fogged, and look
for a better paper."
>
> Is the Ware formula that much more sensitive to the type of paper used
than traditional formulas? Could the sizing, in conjunction with the
sensitizer, cause the "cake icing" effect that I encountered? What could be
the cause of the sensitizer turning dark green within 5 minutes of coating?
>
> I would be greatful for any help solving these problems,
>
> Scott Wainer
> smwbmp@starpower.net
>
> P.S.
> As a side note: I was using both spectral density (orange) and black &
white negatives created on an Epson 1280 using Dan Burkholder's methods. I
did notice that even though I lied to the printer (told it I was using photo
paper) when I used clear transparency film, the negatives came out very,
very thin. I noticed that when I changed from gray-scale to indexed color
that the image lightened dramatically. The image also lightened quite a bit
when I applied the cyanotype curve and when I colorized the image to give it
the orange color. Having a short attention span to working digitally, I
created a gray-scale image, inverted it, boosted the contrast, increased the
density and printed it on the trans film. In short I got a much better cyan
print (barring the above problems) than I did using Dan's methods. Anybody
have any idea what was going on?
>
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