Yellow pigment stain: (Was: Re: Sodium Bisulfite

From: Katharine Thayer ^lt;kthayer@pacifier.com>
Date: 08/24/04-04:17:43 AM Z
Message-id: <412B15C2.62D@pacifier.com>

gdimase@hotmail.com wrote:
>
> Hi Katharine,
> I assume the sodium bisulfite is on a 12% concentration.
> How much time you put the picture in the bath?
> An the you bath it again in a water bath, for how long?
> What about stubborn cases? You keep it longer?
> Let me give you a recent example of what happened to me:
> I was working on a full color print, this picture has an open clean white
> sky therefore the negative section of the sky is totally black.
> I did my first cyano print and everything was fine (sorry I sized the day
> before first with gelatin and glyoxal).
> I go next day for my Blue channel and yellow pigment and the sky comes out
> "yellow", I thought it was stained, next day I did my Green channel and
> magenta pigment and I got a beautiful picture but with the yellow sky (as I
> said out of a black negative).
> I wash it with sodium bisulfite and the stain is still there.
> Yes, I know I can create a new negative and paint the sky on white but I
> want to know what may have happened.

Hello Giovanni,
That's almost certainly pigment stain, not dichromate stain--- a
different issue entirely. I don't mean to discourage you, but it may be
less frustrating for you in the long run to master monochrome printing
before attempting tricolor, at least that's the sequence many people
find most rewarding for gum printing.

Yes, I suppose you could print opaque white over your stain, but I doubt
the result will be the same as the result you would get by printing in
color on white paper.

Katharine Thayer
Received on Tue Aug 24 11:13:54 2004

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