Re: Yellow pigment stain: (Was: Re: Sodium Bisulfite

Same process, same paper, same pigment, same everything also same negative
but the yellow pigment was applied before the cyanotype and NO stain.
Any explanation?
Giovanni

----- Original Message -----
Wrom: BGJSNBOHMKHJYFMYXOEAIJJPHSCRTNHGSWZIDREXC
To: <alt-photo-process-l@sask.usask.ca>
Sent: Tuesday, August 24, 2004 11:15 AM
Subject: Re: Yellow pigment stain: (Was: Re: Sodium Bisulfite

> gdimase@hotmail.com wrote:
> >
>
> > pd Can you instruct me on "pigment stain"?
>
>
> http://www.pacifier.com/~kthayer/html/stain.html
>
>
> How can it happen when there is
> > no light?
>
> Because pigment stain has nothing to do with light.
>
> Katharine Thayer
>
>
>
> My paper is Begger 300 gr. and my pigment manufacturer is
> > "Maimeriblu".
> >
> > ----- Original Message -----
> > Wrom: NNYCGPKYLEJGDGVCJVTLBXFGGMEPYOQKEDOTWFAOB
> > To: <alt-photo-process-l@sask.usask.ca>
> > Sent: Tuesday, August 24, 2004 6:17 AM
> > Subject: Yellow pigment stain: (Was: Re: Sodium Bisulfite
> >
> > > 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 18:10:07 2004