U of S | Mailing List Archive | alt-photo-process-l | Re: gum question

Re: gum question

  • To: alt-photo-process-l@usask.ca
  • Subject: Re: gum question
  • From: Judy Seigel <jseigel@panix.com>
  • Date: Tue, 02 Jun 2009 23:52:27 -0400 (EDT)
  • Comments: "alt-photo-process mailing list"
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  • In-reply-to: <5781.>
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  • Reply-to: alt-photo-process-l@usask.ca

Thanks Loris... Very interesting... Can you give a general idea of how
long your exposures are? As I recall, in the old books, where potassium
dichromate was the norm, it was generally used at 5% (apparently why they
could keep coated paper for weeks before exposing).

Of coure, nowadays -- at least around here -- bigger & faster are better
(or is that just cars?). In any event, can you say what started you in
that direction? Also, maybe you said & I missed that, too -- is this for


On Fri, 29 May 2009, Loris Medici wrote:

Hi Judy, it's ammonium dichromate. (Was shortened as "AD" below...)


29 Mayıs 2009, Cuma, 3:30 am tarihinde, Judy Seigel yazmış:

On Thu, 28 May 2009, Loris Medici wrote:

I always had better results (due my particular working style and/or
materials?) with weak sensitizers; I use only two dichromate strenghts
and 2%. (AD, 1+1 gum/pigment+dichromate.) I also have 10% on hands for
unusual situations though.
Which dichromate is that, Loris -- potassium or ammonium ??????