Re: Printing on fabric

Also silk favours acidic conditions and will be less likely to be degraded
by the coating in an acidic condition. typically silk will be treated with a
mild acidic rinse after washing.

Kate
----- Original Message -----
From: "Loris Medici" <loris_medici@yahoo.com>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Sunday, March 14, 2004 10:39 PM
Subject: Re: Printing on fabric

> Hi John,
>
> --- John <ap@darkroompro.com> wrote:
> > At 11:03 AM 3/10/2004 +0100, you wrote:
> > >You should never use soap with silk, just soak it
> > in water and change the
> > >water many times. If your water is basic, add some
> > drops of lemon acid.
> >
> > My apologies if this is simplistic but why
> > would one want a acidic
> > material ?
>
> AFAIK, lemon acid (citric acid in other words)
> dissolves Ferrous ions. The presence of Ferrous ions
> in the support will cause fogging. I think that's why
> Galina offered the idea of treating silk in citric
> acid. In my experience another effect of citric acid
> is reducing contrast (if not washed off from the
> support before sensitizing) and changing the color(!)
> of cyanotype (if gives a different hue of blue).
> Anyway as I will be rinsing silk in mild potable water
> (that incorporates no ferric or ferrous ions) after
> treating in citric acid, I don't think the support
> will remain too acidic - in fact, acidic environment
> is good for cyanotype as it fades in alkali
> conditions.
>
> Hope this helps,
> Loris.
>
> (Please someone correct my if'm wrong in any of above
> statements)
>
>
>
Received on Sun Mar 14 23:33:12 2004