Réf. : Re: White pigmet for one-layer bichromate.

From: Philippe Berger ^lt;mineurdecharbon@skynet.be>
Date: 11/14/05-10:40:18 AM Z
Message-id: <4378BDF2.000004.00600@PHIL-1G0M44W6VM>

Thank you
It in not a carbon on paper, it is a skin of carbon, it is a carbon image
directly on a skin ofgélatin
The image is a negatif
If you see the negatif white image on a black paper, you obtain a positive

Amitié de Belgique

-------Message original-------
De : Pawel Gega
Date : 11/13/05 21:29:51
A : alt-photo-process-l@sask.usask.ca
Sujet : Réf. : Re: White pigmet for one-layer bichromate.
hmm nice grey scale! How was it sized? What was the brand of used paper?
...and how much contrastive should be the negative (positive) for one-layer?
Best regards, Pawel.
> Hi,
> It is a carbon white on a japan black paper with a white designer gouache
> http://users.skynet.be/philippe.berger/charbonimage2.jpg
> Best regards of Belgium
> Philippe
> -------Message original-------
> De : Katharine Thayer
> Date : 11/13/05 19:21:10
> A : alt-photo-process-l@sask.usask.ca
> Sujet : Re: White pigmet for one-layer bichromate.
> Pawel Gega wrote:
> > Hello,
> >
> > What is the best white pigment for white gum layer on black paper. Is
> > titanium white the cleanest?
> Hi Pawel,
> I would recommend titanium white (PW6) over zinc white (whose pigment
> number I don't remember off the top of my head) which are really your
> only two choices. (Zinc white is often called "Chinese white") The zinc
> is less opaque than the titanium and, in my experience with two
> different brands, tended to dichromate stain as well. You want a good
> quality brand because the inferior brands/student lines often add chalk
> to their titanium white, as the pure titanium oxide is quite expensive.
> > o, is it possible to get white and black tones similar classical B&W ?
> It depends on the paper you use, the pigment mix, the dichromate
> concentration, etc, how long a range you can get in one coat. The only
> white on black I've done so far have been on Arches cover, which is a
> very coarse open paper and as such didn't give a very large range of
> tones. I have an example of how the paper printed for me both unsized
> and sized here:
> http://www.pacifier.com/~kthayer/html/Whiteblack.html
> I got mixed up and used a negative instead of a positive for these
> prints, even though I had the positive sitting right there, and that's
> why the shadows are white instead of black. The original picture was of
> three brown eggs and two white eggs sitting on a white table.
> I was always going to go back and experiment more with printing white on
> black, and ordered some smoother papers for the purpose, but haven't
> found the time so far.
> Katharine Thayer
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Received on Mon Nov 14 10:56:55 2005

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