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 16:11:11 2004