Dick Williams on mon 14 jul 97
There are about15 different process for firing photographs onto pottery that
I know about and probably many more.
The first one developed in 1858 by H. Garnier and A. Salmon of Paris, is
based on the reduction of ferric salts to ferrous by light.Also potassium
bichromate may be used. A white ceramic base is glazed with a transparent
glaze, then after firing a hydroscopic film of gum and bichromate is painted
on and dried in the dark. A high contrast positive transparency is placed
over the gum bichromate film and exposed just enought so that the image is
hydroscopic in the area that should be dark and nonhydroscopic in areas that
should be light. A fine mixture of flux and mason stains is dusted on to the
film and if the humidity is high enough (using a mask you can breath on the
film ),the picture will develop slowly. Be sure to use a resperator to
protect yourself from the dust and rubber gloves when handling bichromate
which can be hazardous. If the picture is too dark the exposure was too
short,if too light exposure was too long. Different colors can be used in the
same image.The image is refired to the maturing temperature of the glaze.
Another similar method is to use the chemicals in the Blue Print Process.
This only gives a brown image and was written up in Ceramic Monthly a few
years ago.
This method and many others can be found in the Encyclopedia of Photography,
Bernard E. Jones Ed., Arno Press, New York 1974 (Reprint of 1911 ed. of
Cassell's Encyclopedia of Photography, London).
Dick Williams in sunny Wilmington, NC waiting for the next hurricane to
hit.We got washed away by two last year, Bertha and Fran.
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