Katharine,
You do like to experiment! Perhaps all the gum printers are like that. I am not surprized that the gum print done by "your method" looks best. After all you have done countless experiments to arrive at it. Taking somebody elses method would require some fine tuning. Variables like paper, sieze, dichromate to gum ratio, development style, etc are at play here. Some of them might be important contributors to the method.
I do have a couple of prints with very precise notes I could send you a scan and detailed description if you are interested.
My first inclination is that you gum layer is too thick. You can achieve high DMAX with either thicker gum layer or thinner, but more pigmented layer. Do you know what is the pigment concentration in your mix? Perhaps paper/sieze is a contributor as well.
Thanks for posting the pictures and as always interesting discussion.
Marek
> Date: Fri, 30 Nov 2007 20:55:39 -0800
> From: kthayer@pacifier.com
> Subject: Bleach-development with gum
> To: alt-photo-process-l@usask.ca
>
> This isn't working very well for me; I don't know why. I've
> posted a couple examples from an afternoon's efforts.
>
> The main dilemma seems to be that if I leave the print in the bleach
> for longer periods of time (10-15 minutes) I get blotching and
> mottling of the image, (both with highly pigmented and normally
> pigmented mixes of lamp black) but if I soak it in the bleach for
> shorter periods of time (1-5 minutes) then development is too slow
> for my patience. Perhaps I've overexposed too much at 3x normal,
> but I wouldn't have thought so. The bleach I'm using is Western
> Family brand; ingredients are listed only as Sodium hypochlorite 6%,
> "Other ingredients" 94%. I've used it diluted at 15ml/liter of
> water. Gum coating mix is, as always, 1 unit gum/pigment: 1 unit
> saturated ammonium dichromate. Arches bright white paper, sized with
> gelatin/glyoxal. I've included a normal print, for comparison.
>
> http://www.pacifier.com/~kthayer/html/Bleachdev.html
>
>
>
> On Nov 27, 2007, at 1:52 PM, Marek Matusz wrote:
>
> > Very interesting thread. I was in the Big Bend NP hiking and taking
> > pictures, happy without a computer or cel phone for a few days. I
> > only got to read some of the emails now.
> > Here is my comment from the practical standpoint of a gum printer.
> > My one coat gum prints have eveloved to a practice that gives
> > maximum darks and long (relative) tonal range of the final print
> > (not to be confused with long negative density range). Some of my
> > prints were included in the travelling portfolio last time around.
> > Here is a description of my pratice.
> > Coat the paper with gelatine / harden it.
> > FOr the gum layer I prefer highly pigmented carbon black.
> > Use longer exposure (3 to 5 times normal exposures). I really have
> > not tried to push it even further.
> > Soak in water to remove dichromate.
> > Develop in a weak chlorox solution. My dilution is about 20 cc/
> > liter of water. Could be as little as 10cc if I want slow action or
> > as much as 40 to 50. Once the print starts bleeding the pigment I
> > place it in water and watch for a few minutes following the
> > development. If the development is slow, dip back in chlorox for a
> > few minutes. The reason for moving it back and forth is that the
> > action of chlorox continues for a few minutes and it is easy to
> > just wash the gum layer completely.
> > Actually I use this method a lot for my tricolor gum prints as well.
> >
> > How close is that to direct carbon? I call it gum, but it has all
> > the ingredients mentioned in this discussion, geletine, gum,
> > chlorox (or Javelle water version)
> > Marek
> >
> > > Date: Tue, 27 Nov 2007 07:58:31 -0700
> > > From: zphoto@montana.net
> > > Subject: Re: The Fresson/Arvel Process
> > > To: alt-photo-process-l@usask.ca
> > >
> > > Thank you, Dave!
> > >
> > > However, the only thing nice and generous about me is my butt
> > after sitting
> > > on it all weekend, 24/7, taking notes out of the 300+ pages I
> > took digipix
> > > of at Geo Eastman House. But it is DONE!!! One further milestone.
> > >
> > > Snippet from an 1896 book I told you I'd share about a possible
> > Artigue
> > > formula; they were always trying to guess at it..Since Artigue
> > died with
> > > his secrets and the Fresson family doesn't seem to be willing to
> > share
> > > theirs, it is interesting to look at discoveries before the
> > Artigue paper
> > > that might have been in the air. So this may be worthless but
> > what the
> > > heck:
> > >
> > > "1863 Mr. Blair of Bridgend took plain paper, coated it with
> > gelatine and
> > > dried; then next coated with albumen mixed with a little syrup,
> > and dried.
> > > Then floated on water and blotted and carbon powdered pigment was
> > brushed
> > > onto the surface in a thin film on top of the albumen. Sensitized by
> > > floating on a solution of pot bi. He did not use gum on top of
> > the gelatin
> > > because it did not take kindly to it and it was more apt to run
> > together
> > > under the operation of the brush and leave small blank spaces,
> > and was also
> > > tackier under moisture, and took up too much pigment." (not a
> > direct quote)
> > >
> > > I think that electron microscopy nowadays says that gum IS in
> > Fresson paper
> > > along with gelatin (at least, that is what I read in Chakalis'
> > patent) but
> > > the way this paper is described in the text is even, translucent,
> > and
> > > velvety like the Artigue. It seems that when a lower solution of
> > pot bi
> > > (like 2-5%), warm or hot water development, sawdust, eau de
> > Javelle are
> > > used, gelatin is in the paper. I marvel at their exposing the
> > direct carbon
> > > paper for HOURS in the SUNLIGHT before developing it in Javelle.
> > >
> > > BTW, any who may be confused about the differences between carbon
> > printing
> > > and direct carbon (not you Sandy, John, Art) of which we are
> > talking, carbon
> > > printing is the term nowadays used to refer to a transfer process
> > where the
> > > tissue of exposed gelatin is transferred to another piece of
> > paper, but back
> > > in "the day" the term "carbon printing" referred to the gum process
> > > originally. Then the term was swiped in a drive-by for the carbon
> > transfer
> > > process so towards the end of the century the term "direct
> > carbon" came into
> > > use for both gum printing and such things as Arvel, Artigue, etc.
> > papers
> > > even if carbon pigment wasn't used. So when researching I always
> > have to
> > > xerox articles that talk about pigment printing, carbon printing,
> > direct
> > > carbon, bi-gum, gum-bichromate (that little hyphen becomes
> > important in
> > > searches), etc. Direct carbon was not transferred to another
> > piece of paper
> > > hence the operative word "direct".
> > > Chris
> > >
> > >
> > > ----- Original Message -----
> > > From: "Dave Soemarko" <fotodave@dsoemarko.us>
> > > To: <alt-photo-process-l@usask.ca>
> > > Sent: Tuesday, November 27, 2007 6:26 AM
> > > Subject: RE: The Fresson/Arvel Process
> > >
> > >
> > > > << There are no immediate plans on my agenda to make the
> > process I use
> > > > available on the market. But like yourself I am willing to help
> > others to
> > > > experiment with the Direct Carbon system by pointing them
> > towards relevant
> > > > published information. >>
> > > >
> > > > John and Chris,
> > > >
> > > > Both of you are very nice!
> > > >
> > > >
> > > > Dave
> > > >
> > > >
> > >
> > >
> >
> >
> > Connect and share in new ways with Windows Live. Connect now!
>
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