Re: RE: Digital negatives for gum printing

[Judy Seigel <jseigel@panix.com>]

On Fri, 3 Aug 2001 Smieglitz@aol.com wrote:

> ... An in-camera film is probably the best, unless you want to
> change something about the image.

Or unless you want to do a style of photography incompatible with big
stationary camera. And/or like a style of gum printing that uses negs of
different densities for different coats.

> I came to this conclusion after many attempts at printing digital negatives
> using inkjet or laser negatives and discovering to my amazement that Stephen
> Livick used halftone negatives to achieve his magnificent technical results.

I have an idea that Livick's "magnificent technical results" may accrue as
much from his method of coating -- by spray gun -- as his negatives. I've
printed halftone negatives & found them very interesting, but with the
vagaries of hand coating (even when "perfectly" applied) they lack the
color-photo *look* of Livick's prints. The "touch of the hand" is
apparent, although perhaps subliminally in any hand-coated print, I
suspect. I myself find that a plus, life-giving as it were, but unrelated
to the negative.

> ... I see the
> contone negatives as printing miniature islands and peninsulas on the surface
> of the paper, with the shoreline getting eroded here and there as the soluble
> gum takes part of the insoluble gum away with it as it develops.  So h
> alftones produce sharp columns, and contones produce landscapes.

Well again, sounds like description of difference between handcoating &
spray coating.

> And then suddenly along comes the Epson 1160 and Cone's piezography.  Another
> flip-flop for me.  There is absolutely no visible dot with this stuff.  It's
> in a different class.  And the curves (very simple BTW) make the stuff behave
> when making negatives.
>
> ...  In my opinion, you have to be using AZO or Centennial to get
> the same sort of feeling from a silverprint and these still are far different
> than the quadtones.  The quadtones are like Platinum mixed with french
> vanilla ice cream.

But in my experience the "feeling" changes according to number of coats...
or with each coat. Are you printing color separations? Then you may be
comparing apples & oranges.

> ... The laser printers fail for the same reason.  At
> anything above 300 dpi, more printer artifacts occur (on the lasers I've
> used)-negatives get banded, smooth tonal areas suddenly print with several
> minutely different tones, etc.  So we are back to lower resolutions and
> larger dots.

As an aside -- IME banding in laser print is a factor of the ^%$*&^!!**
cartridge. When you get lucky with cartridge, no banding, when not, plenty
(even from original manufacturer).

> With the piezography system and the proper Photoshop curve, you can fit the
> image scale into the scale of the gum emulsion.  No posterization, no
> multiple negatives for highlights vs. shadows, no visible halftone, etc.
> IMO, it makes for a better negative, simplifies the entire process, and
> produces a better gum print.

Why do you fit negative to scale of the emulsion?  For color separations?
(When I STOPPED doing that for multicoat printing my gums took a great
leap forward.)

> ... switched from ammonium dichromate to the potassium salt, and ...
> I'm sure others will counter with ammonium dichromate is better ..

For what it's worth, I found that when concentration was the same, results
were very similar...

But I'm curious about your "photoshop curve."  That's one you made
yourself, not by a paid consultant?

Judy