From: Ed Buffaloe (EdBuffaloe@UnblinkingEye.Com)
Date: 03/09/03-04:48:17 AM Z
Yep. It was powdered lamp black. Another list member sent me a private
note asking if I had washed thoroughly after clearing the first clear coat
with sulphuric acid. I recall simply hanging the print up to dry. I take
it I need to wash thoroughly to get the acid out?
----- Original Message -----
From: "Christina Z. Anderson" <zphoto@montana.net>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Saturday, March 08, 2003 7:00 PM
Subject: Re: First Gum Print
> But Dave,
> OH, maybe THAT's it! I used not powdered pigment but tube pigment!
> Ed, did you use powder?? But that's the ratio I was using that worked; 6g
> lamp black *pigment* to 12ml gum to equal amounts of 24% am di
sensitizer.
> Yes, it is way over the norm, but my prints turned out fine on unsized
Rives
> BFK (unshrunk, tho, so still size from manufacturer in the paper). You
know
> what I realized, tho, too; Ed sized with a layer of unpigmented gelatin
and
> then cleared. Maybe this is what's up--the new layer of hardened colloid
> won't release from the old layer of hardened colloid...
> And, my prints cleared easily in under an hour. I was able to see
> image within the first 10min soak.
> Hey, Dave, could you jpeg me an image of yours with the 1g/100ml
ratio,
> a one coat gum, so I can see how deep your blacks are? At the dilution of
> 3g *pigment* to 50 I have a very pale image, but I'd love to test that
> against 1g *powder*.
> Chris
> PS are you sick of winter? I'm driving to Moab....
> ----- Original Message -----
> From: "Dave Rose" <cactuscowboy@attbi.com>
> To: <alt-photo-process-l@sask.usask.ca>
> Sent: Saturday, March 08, 2003 5:47 PM
> Subject: Re: First Gum Print
>
>
> > "4ml gum with 2 grams lamp black powder" WOW! No wonder your print is
> > totally black!
> >
> > I'm using 1 gram lamp black powder per 100ml gum. At that ratio, It's
> > strong enough for acceptable 1 coat prints. IMO, you're using way too
> much
> > pigment in the mix, leading to massive staining that obliterates any
> image.
> >
> > Dave in Wyoming
> >
> > From: "Ed Buffaloe" <EdBuffaloe@UnblinkingEye.Com
> >
> > > Pre-shrunk & sized Fabriano Uno. Precoat with unpigmented gum--expose
> for
> > 30 minutes under UV. Soak and clear chromium stain with sulphuric acid.
> > Coat with 4ml gum with 2 grams lamp black powder plus 4ml saturated
> solution
> > ammonium dichromate. Expose through 8x10 negative under UV light for 25
> > minutes. The negative is an 8x10 developed in a conventional developer
to
> a
> > d-max of 1.26.
> >
> >
> >
>
>
>
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