From: Liam Lawless (liam.lawless@blueyonder.co.uk)
Date: 03/08/03-08:59:55 PM Z
Hi Folks,
I'm no gum printer, but does gum arabic maybe have a shelf life, after which
it hardens "spontaneously" after drying out (i.e. after coating)? And is
contamination with glyoxal or similar too far-fetched to consider?
Liam
-----Original Message-----
From: Christina Z. Anderson [mailto:zphoto@montana.net]
Sent: 09 March 2003 01:01
To: alt-photo-process-l@sask.usask.ca
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.
>
>
>
This archive was generated by hypermail 2.1.5 : 04/22/03-02:37:25 PM Z CST