From: Katharine Thayer (kthayer@pacifier.com)
Date: 01/30/02-04:01:19 AM Z
Sarah Van Keuren wrote:
>
> Just completed cyanotype (old formula) comparisons of four different
> ways of producing inkjet negatives on photo-quality inkjet paper (as
> it comes out of the box and also made transparent with canola oil) and
> on inkjet transparency film. I'm using a scan of an 8x10 b/w pinhole
> negative and producing the negatives on an Epson 740. I printed, on
> both the paper and the film, 4 renditions of the file: 1) all black
> ink 2) RGB color 3) Dan Burkholder's colorized grayscale method 4)
> Dan's color table method. Number 3 worked by far the best and his
> number 4 was the flattest and weakest of all four. The RGB negatives
> did function as stronger light resists than the ones in black ink.
> Also I found that the transparency film worked faster and gave a more
> vivid rendition of the Fairmount Water Works (my subject) than the
> transparentized paper but I can imagine how for some images the
> softness of the oiled paper would work well. The unoiled paper was
> hopelessly slow and fibrous.
>
> Haven't had a chance to compare these negatives in gum bichromate. I'm
> wondering if gum might be more sensitive to the lightblocking effects
> of the pure orange color table method than cyanotype was.
The message I'm responding to here is dated Sunday 19 March 2000! Since
I've been testing negatives on Pictorico for gum, I decided last night
to go back through my folders and read everything I'd saved on the
subject, and Sarah's message turned out to be the most interesting to
me, since it parallels exactly tests I've been running for gum in the
last two weeks. I can't find anywhere a later report of what happened
when/if Sarah went on to try inkjet-transparency negatives with gum; I
would love to have an update.
My results with Pictorico for gum have been on the whole disappointing.
I decided to try transparency material again (Ive printed mostly from
digital paper negatives for years) after being intrigued with the tonal
rendition I get from direct contact prints on gum using in-camera large
format negatives, and wanted to see how close I could get to that with
an inkjet transparency; the answer so far (I've gone through two boxes
of Pictorico just testing) is "not very close."
I don't know whether my information will be useful to anyone, since I'm
not doing quadtone printing and I'm still using an "ancient" Epson Photo
EX, purchased in... 1998 I guess, and am determined not to replace it
any time soon. (I'm also still driving my 1988 Honda; it just passed
200,000 miles the other day.) But on the chance it might be useful to
someone, here's what I've found:
The tests I've run were the same for gum as Sarah describes above for
cyanotype: negatives printed by (1) black ink only (2) black printed in
colored inks (3) Dan Burkholder's colorized-by-fill method for spectral
density (4) Dan's color table method for spectral density. I've tested
these both on Pictorico and on paper (subsequently oiled) using the same
image throughout, and experimenting with various curves and transfer
functions to accommodate the vagaries of the Pictorico material itself.
The results: (1) Though the *negative* printed in black ink looks coarse
and grainy, looks in fact unacceptable as a negative, it makes the best
gum print (smoothest tonal gradations, best approximation of the tonal
scale available from the negative, best overall approximation of the
effect I get from a large format negative directly contact-printed). (2)
The second-best gum prints I got were from oiled paper negatives,
printed in black with color inks and no curve other than the curve to
get the image the way it should be, in other words my standard procedure
for producing negatives for years. (3) The fill-colorized orange
negatives on Pictorico have too much density in the highlights and not
enough density in the shadows, regardless of how the curve and the fill
opacity are manipulated. Result: a very posterized, high-contrast gum
print, not interesting to me. (4) Printing black with colored ink on
the Pictorico doesn't work. The ink puddles and migrates to edges before
it can dry, making white halo lines around all objects on the gum print.
(5) Dan's color table spectral density was the least promising of all.
It's really interesting to me that he can print a decent platinum print
using this method, since for gum it doesn't work at all, at least not in
my shop. It makes a "lovely" faint negative, (you have to hold the
negative just at the right angle to even see the image in it) but it
doesn't give enough density to make a recognizable image in gum; even
increasing the density of the two colors to 100%, the resulting gum
print at any exposure is mud.
By the way, the good news about printing with standard Epson inks on
Pictorico is that the ink dries quickly; I hold it under my lamp for
about 30 seconds and it's dry, and then it can be touched without
marking the image. the one thing it can't stand is water; water touching
the Pictorico film anywhere leaves an ugly white spot that prints. This
creates quite a problem for me since I live in a rainy climate and my
studio is a separate building from the house, where the computer is. I
carry the negatives to the studio in a canvas briefcase enclosed in a
bigger tote bag, so that no water will get on the briefcase that could
transfer to the negative when removing it.
No doubt I'll be told I should update my printer and invest in the
piezography or other quadtone system; that is not going to happen. I've
got a show opening in two months and everything I've done up to now has
been promised elsewhere, so I have no inventory whatever, and I've got
to be flat printing from here on out, not messing around with testing
and trial and erroring. I'll print from a combination of digital paper
negatives, large format negatives, and probably some of these black-only
Pictorico negatives, depending on what works best for the image.
Cheers,
Katharine Thayer
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