Makes a lot of sense. A soft bottom layer with a hard top layer. Since the
problem of any direct process is that the development is from the bottom.
In this way you can easily get flaking. I would expect the pigment to be in
the bottom layer, but sandwiched in between seems logical as well. The
thick hard top layer functions to hold back the flaking. If the top layer
is really really hard then the dichromate will have little effect on it.
The trick is then how to get the developed soft stuff from underneath to
wash free from the image during development? Say for instance the paper was
laser perforated all over, this would leave little wells for the pigment to
escape through leaving the hard top layer protecting the image from
flaking. May piercing through the back with a zillion microscopic holes
just up to the first layer of pigment?? Another idea would be use some kind
of abrasive material during development. Maybe sawdust?? <grin> The idea of
the sawdust would be to break the hard upper crust and free the pigment
from the developed bottom, and not really not to develop out the whole image.
The final powdering of the pigment is a mystery?? Is it possible the image
is intensified at the end with a light dusting on process. Depends on
whether the piece was processed or unprocessed.
Nice work Sandy! It gives me some ideas on working with gum.
--Dick Sullivan
At 02:11 PM 1/12/98 -0400, you wrote:
>
>Last week I promised to post the results of the analysis of a piece of
>unprocessed Fresson paper. As I mentioned, the analysis was made on a piece
>of paper manufactured in the 1940s or early 50s. The information was given
>to me in the early 80s. Based on the stated source of the information and
>the credentials of the person who gave me the information I believe it to
>be accurate and correct. The paper from which this analysis was made is of
>a very deep, neutral black color.
>
>According to the analysis, the Fresson paper in question consisted of the
>following, in this order:
> 1. a paper base, followed by
> 2. a thin coating of soft gelatin with a relatively thin black pigment
> dispersion, with a slight cool, ultramarine tone, followed by
> 3. a thicker layer of gelatin, harder than the first, with no pigment,
> followed by
> 4. a powdering of a very fine, dry pigment
>
>Hope this information proves interesting to some of you.
>
>Sandy King
>
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