U of S | Mailing List Archive | alt-photo-process-l | Re: Clues From Echague. One.

Re: Clues From Echague. One.

Hi Loris, I would, from experience, strongly suggest that you do not harden the base layer, as one might do if this were a sizing, because it needs to allow the surface pigment layer to penetrate into it when development takes place. It would be appreciated if you would report back on the use of Agar-Agar as the binder for the surface pigment.
Best wishes for now.
John - Photographist - London - UK.
----- Original Message ----- From: "Loris Medici" <mail@loris.medici.name>
To: <alt-photo-process-l@usask.ca>
Sent: Sunday, May 27, 2007 7:31 PM
Subject: Re: Clues From Echague. One.

John, thanks for sharing.

When I saw mucilage, the first thing that came into my mind was Agar-Agar, I was preparing to write a question if Agar-Agar is a good option for this purpose but then I saw its name inside the list of "possible" materials...

I may try Agar-Agar and Direct Carbon later since there's another carbon printing method (a non-toxic variant by Halvor Bjoengaard) - which I also want to try - that uses this material.

May I request another clue? Should one harden the underlying gelatine layer? (My bet would be to not harden...)


Quoting John Grocott <john.grocott403@ntlworld.com>:

In either process the paper is coated with a layer of gelatine but which supports, only in the Direct Carbon process, a layer of pigment dissolved in a mucilage, instead of being incorporated in the same base gelatine as occurs in the Carbon Transfer process.
So, to recap.The paper forDirect Carbon is made of a thin layer which is generally gelatine; on this layer is coated the pigment dissolved in a vehicle such as Gum Arabic, Tragacanth Gum, Lichen, Agar-Agar etc., but the base coating is always formed of a thin layer of gelatine in direct contact with the paper support.

The result of this way of preparing the paper, for one thing, is the various qualities that can be obtained according to the proportions of gelatine and gum muclage used and also the thickness of the pigmented surface layer and the extent to which it penetrates into the base layer when development takes place.