U of S | Mailing List Archive | alt-photo-process-l | Re: Seeking Information on 2 problems with Gum process

Re: Seeking Information on 2 problems with Gum process

Keith,
The ammonia turns the cyanotype lavender, correct? Does this interfere with your color balance?

And have you ever returned the gum print to an acid state and seen it revert back to blue again or no? In other words, I wonder if it would change over time if returning to a more neutral or acid condition.

One other question--does the ammonia eat away at your gum layer?
Chris


----- Original Message ----- From: "Keith Gerling" <keith.gerling@gmail.com>
To: <alt-photo-process-l@usask.ca>
Sent: Wednesday, April 30, 2008 7:29 AM
Subject: Re: Seeking Information on 2 problems with Gum process


As my well-water is somewhat alkaline, the cyanotype layer bleaches
out slightly during the subsequent gum stages.  My approach is to
overprint the cyano layer to the point where it is much too dark, and
then to bleach it back to where I want it when the gum is finished.  I
use dilute ammonia.



On Wed, Apr 30, 2008 at 5:50 AM, cadunn <cadunn@vt2000.com> wrote:
Henry wrote:
but I found it much better to dilute

> the coating solution with anything up to six or seven times its own > volume
> with water. You can hardly see it as you coat it, but the blue is there > OK
> and you can give it full exposure. Dilute solutions seem to need rather
less
> exposure than full-strength ones.
>


lol, Henry -- your msg. came JUST after I had coated the paper and was
planning on a much reduced exposure time, which is all at this point in my
learning curve that I knew to do --

So, next iteration of cyanotype stage variation belongs to you!

Thanks