RE: Digital negatives for gum printing

[Keith Gerling <kgerling@ameritech.net>]

Everything Katherine says, I second!  From some of the mail I get, I am
somewhat concerned that people either think I have a compromising nature, or
that I don't have the sense to appreciate subtle details.  Seriously, I have
spent considerable effort with a number of printers, inksets,
papers/vellums/transparencies, profiles, output curves, and combinations of
all trying to  obtain better gum prints.  I would really appreciate seeing
ANY comparisons of gum prints using:

1) Black vs. color demonstrating color is better
2) Black or color vs. Quadtone demonstrating quadtone is better
3) Waxed/oiled paper vs. Pictorico demonstrating Pictorico is better
4) Any newer Epson printer vs. the "old beasts" of yesteryear, demonstrating
the newer stuff is better

Now THAT would be some handy information!

Keith


-----Original Message-----
From: Katharine Thayer [mailto:kthayer@pacifier.com]
Sent: Friday, August 03, 2001 7:48 AM
To: alt-photo-process-l@sask.usask.ca
Subject: Re: Digital negatives for gum printing


Keith's point (below) is the point I was trying to make earlier, but
from the responses of a couple of private correspondents, I'm gathering
I didn't make it clearly enough.  It's not that negatives for gum might
as well be low resolution because soft mooshy gum can't manage details
anyway; it's that quite detailed gum prints can be made from low
resolution negatives, and an increase in resolution in the negative
doesn't necessarily result in an increase in sharpness in the gum print
itself.

I've let all this piezo stuff go by me for months without paying any
attention to it, since I've been satisfied with my negatives and my
prints, but now my curiosity has suddenly been aroused.  If someone
could show me a gum print that demonstrates that quadtone negatives,
piezograph or otherwise, result in more wonderful GUM PRINTS, not just
more wonderful NEGATIVES, I might be tempted to race out and try to grab
up one of the few remaining 1160s. I've heard a lot of talk about
negatives and curves and ramps so far but not much about gum prints from
those negatives, and what I've seen so far in terms of published results
shows only that you can compress the tonal scale of the negative to
match the tonal scale of the gum to print gum in one coat; this has been
done before both digitally (without quadtones) and analoguely (sp?) and
it's not something I want to do, preferring to lengthen the tonal scale
of the gum to match the tonal scale of the negative by multiple printing
rather than compressing the tonal scale of the negative to match the
tonal scale of the gum. So I guess I'll rephrase and ask the original
question again, as I'm not sure in all this discussion anyone has
answered it: What does quadtone printing of negatives for gum printing
get you in terms of improvement to actual gum prints?

As to black versus quadtone inks for negatives, I come down between
those two positions, preferring to print "black" by using the colored
inks.
Katharine Thayer




Keith Gerling wrote:
>
...... I should point out that my limited
> experience in printing single and double coat gums from ONE negative
> demonstrates that very detailed gum prints can be had from negatives
printed
> just around 300 dpi. <snip>  The gist is: don't sweat trying to increase
> that dpi count: you may not experience any gain.  When printing gum, I
fail
> to see any improvement in detail when the printer is used at greater than
> 300 dpi.  Of course, the cheap paper I use might not even be able to
resolve
> greater than 300, so who knows?
>