Keith,
I have been using carbon black powder from Daniel Smith. Gum bleach development requires higher density negative then normal gum. I would say something more like palladium negative density would be fine to start with. If you can email me a scan of your work I can perhaps troublesoot it.
Marek
> Date: Tue, 1 Jan 2008 19:47:57 -0600
> From: keith.gerling@gmail.com
> Subject: Re: direct carbon or gum bleach development
> To: alt-photo-process-l@usask.ca
>
> Hi Marek,
>
> My attempts look atrocious. What kind of pigment are you using for this?
>
> thanks!
>
> Keith
>
> On Dec 20, 2007 4:05 PM, Keith Gerling <keith.gerling@gmail.com> wrote:
> > Awesome, Marek. This is what I want MY prints to look like. Forget
> > all that multi-coat nonsense.
> >
> >
> > On Dec 20, 2007 2:28 PM, Marek Matusz <marekmatusz@hotmail.com> wrote:
> > >
> > > All,
> > > More experimentation with gum printing and bleach development.
> > >
> > > I was intrigued by Loris's results with using unsized paper. I thought that
> > > it would give a rather bad stain. My tricolor gum practice certainly led me
> > > to believe this. However on numerous occasions I did observe that edges of
> > > paper that I used which did not have gelatin size gave a darker, more
> > > uniform black. SO last week I tried to use single sized paper, fresh and
> > > unsized Fabriano Artistico, and a throw away gum print that has been soaked
> > > over and over, but had a reverse side of Fabriano paper quite clean. My
> > > overall conclusion with this set of prints is that I liked unsized paper and
> > > soaked paper best. They gave crispier prints. Perhaps this technique likes
> > > the gum to be tied up with the fiber of the paper and the bleach development
> > > can give clear paper base. So I would advocate use of straight watercolor
> > > paper, no need to size. I have not tried any other brand, but I should have
> > > some at hand and will try next printing session.
> > >
> > > I have also experimented some more with pigment density. I had a more
> > > concentrated carbon stock of 3.75% carbon in 14 baume gum, that is 50% more
> > > then in my last set of experiments. The solutions are left over from dozens
> > > or maybe hundreds of experiments done in the last two years. Once the water
> > > dried out this would result in 3.75/0.27=14% carbon/solid gum mixture (I
> > > assume 14 baume gum is 27%). This is definitely black black. Beautiful
> > > velvety matte texture of the deep black to take your breath away. Scan of
> > > the print here. This print was made on unsized Fabriano Artistico paper
> > >
> > > http://picasaweb.google.com/marekmatusz1/GumBleachDevelop/photo#5145909559997921266
> > > The mid tones are a little bit darker on this screen that in reality. Maybe
> > > even the two tones of black on the very edge are visible. Very outside, had
> > > most exposure (I uped the exposure to 6 minutes from last time) and next to
> > > it is somewhat lighter edge from exposure through blank part of transparency
> > > (Pictorico). This is a further illustration of how a fine tonal gradation
> > > can be achieved with this method.
> > > I have also included an detail of the print scanned at 300 dpi:
> > >
> > > http://picasaweb.google.com/marekmatusz1/GumBleachDevelop/photo#5145909521343215586
> > > Happy printing
> > > Marek
> > >
> > >
> > > ________________________________
> > > Don't get caught with egg on your face. Play Chicktionary! Check it out!
> >
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