clearing dichro stain with sulphuric acid was Re: (Gum) Tonal scale

Pete et all,

I don't know if you saw Katharine experiment (link below) or not but the
reason I ask the question was to find out if the one(1%) solution of
sulphuric acid you've been using all these years would leave a noticable
tone like the NaCl and the other stuff did leave???

Yves

----- Original Message -----
From: "peter" <temperaprint@blueyonder.co.uk>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Tuesday, December 06, 2005 9:35 AM
Subject: Re: (Gum) Tonal scale

> Dear Yves.
>
> I have used a one(1%) solution of sulphuric acid to clear the brown
> dichro stain for the past twenty years with no ill effect in both Gum
> and Temperaprint.
>
> Best wishes
>
> Pete
>
>
>
>
> On 6 Dec 2005, at 00:38, Yves Gauvreau wrote:
>
> > These are very interesting results Katharine, thanks for sharing them
> > with
> > us.
> >
> > I ear that some acid (sulfuric acid maybe) could help to clear the
> > dichromate, I'd be curious to see or ear about a similar test using
> > it???
> >
> > Thanks
> > Yves
> >
> >
> >
> > ----- Original Message -----
> > From: "Katharine Thayer" <kthayer@pacifier.com>
> > To: "alt photo" <alt-photo-process-l@sask.usask.ca>
> > Sent: Sunday, December 04, 2005 9:50 AM
> > Subject: Re: (Gum) Tonal scale
> >
> >
> >> I accidently sent this to myself instead of to the list, (still
> >> figuring out my new mail program) so I'm sending it again, to you.
> >>
> >> On Dec 3, 2005, at 1:00 PM, Katharine Thayer wrote:
> >>
> >>>
> >>> After I wrote that about dichromate stain, I remembered that I have a
> >>> page showing the color of unstained gum, of dichromate-stained, and
> >>> of
> >>> cleared stained gum, on my site; here it is if anyone is interested:
> >>>
> >>> http://www.pacifier.com/~kthayer/html/gumcolors.html
> >>>
> >>> The samples don't show different tones, because it was gum that was
> >>> exposed without a step tablet or any kind of negative, just hardened
> >>> gum. that's when I was working on that project of making gum for
> >>> chemical analysis.
> >>> kt
> >>>
> >>
> >
> >
Received on Wed Dec 7 04:11:12 2005