U of S | Mailing List Archive | alt-photo-process-l | Re: Bleach-development with gum

Re: Bleach-development with gum

Loris, thanks for paint information. I had thought of asking this question earlier, when I was puzzling about pigment amounts, but then I realized that even if we were using the same pigment, but different brands, there would be no way of comparing how much pigment, as different manufacturers use different amounts of pigment in their paints. So we'd still be comparing apples and oranges. At least when comparing with Marek's powdered pigment, there was an exact measured amount of pigment to compare to; in our case there'd be no basis for comparison at all.

Lamp black is a very strong pigment; ivory black is a weaker pigment, so you'd use more ivory black paint to get the same saturation of black as I'd use of lamp black. And then there's the difference in brands; even if we were both using the same pigment we couldn't compare the amount of paint, as different brands use more fillers and binders and less pigment than others. So it's simply not useful to compare amounts of pigment across pigments and brands of paint.

Marek's right; the only way to compare pigment amounts is if we all use powdered pigment, but as I said earlier, that's not going to happen here. I did an experiment with powder one day and it took me a couple of weeks to eliminate all traces of blue from my work area.


On Dec 7, 2007, at 9:14 AM, Loris Medici wrote:

Premixed paint; Schmincke Ivory Black and a little bit Neutral Gray for the
successful print. I don't use powdered / pure pigments yet -> it sounds
messy :) But I may opt to use them later, for economy reasons.


From: Marek Matusz <marekmatusz@hotmail.com>
Reply-To: <alt-photo-process-l@usask.ca>
Date: Fri, 07 Dec 2007 17:05:35 +0000
To: <alt-photo-process-l@usask.ca>
Subject: RE: Bleach-development with gum

Just curious. Did you use powdered pigment or some kind of premixed paint
for you gum?