U of S | Mailing List Archive | alt-photo-process-l | Re: ferri sesquichlorati

Re: ferri sesquichlorati

Hi Chris, Yes fun :-)

If you do anything with it at some point, I would like to know.

I have mostly been over at the Carbon list for a long time, but studies
slided over into kind of gum recently so "moved" back here, so have missed
that dichromatype, but will do a search.

(page 174 in Kosar describes a silver system for "carbon" or relief images,
I also have an article somewhere dealing with that, it could maybe also work
with gum, but is probably a mess to get too work :-) It is somewhere far
down on my to do list.. Thought I should try to mix some liquid light and
pigment and see what can be done as a start...)

Have seen a brief descriptions of ferric used as a crosslinker for
holography with PVA.. But have yet to chase down the references..

BTW, Is there a maximum number of layers for gum, one book I have claim
twelve or so, but have seen other claims of 20 .. ?


On 10/21/06 12:08 AM, "Christina Z. Anderson" <zphoto@montana.net> wrote:

> Halvor,
> This is really fascinating...
> First of all, I found the quote:  "...earlier observations by Alphonse
> Poitevin in 1863, that ferric salts cause gum and similar colloids to harden
> and become insoluble in water, whereas ferrous salts do not." p. 53 Ware,
> Cyanotype.
> I had heard this once before on the list--I think Judy brought it up a long
> while back--and thought it an interesting phenomenon, but didn't know where
> it came from until you brought it up.
> I dunno, might just try mixing a bit of A and B and plopping it in my gum
> solution as per normal--it'd have the dichromate in it to harden, and the
> cyanotype would just get exposed at the same time?  Might be worth a try.  I
> never thought about this until China Hamilton talked about adding the silver
> nitrate to the mix--a dichromatype he called it.
> Chris