DShack (TSHACK@SILVER-BAYOU.COM)
Sat, 03 Jul 1999 16:32:20 -0700
Ah, this was discussed on the list back in 1996. Nobody seemed to hold much
promise for it, citing some peeling of color pictures taken of Wilhelm II,
calling it a complete failure. That might have been a gum process. it
seems that the iron salts process might have had better luck.
-----Original Message-----
From: DShack <TSHACK@silver-bayou.com>
To: alt-photo-process-l@skyway.usask.ca
<alt-photo-process-l@skyway.usask.ca>
Date: Saturday, July 03, 1999 4:08 PM
Subject: Printmaking without light
>I was just out cruising used bookstores trying to find some of these
>antiquated reference texts that some of you quote from, and that I covet.
>
>I happened across one book called "Henley's Formulas for Home and Workshop"
>originally published in 1907 and 1927. This is a reproduction copy I have.
>Though it has an extensive section on photography, in another section it
had
>something called "photography without light", or catatype. I'll quote what
>it says:
>
>"It is a well-known fact that the reactions of the compounds of silver,
>platinum, and chromium in photographic processes are generally voluntary
>ones and that the light really acts only as an accelerator, that is to say
>the chemical properties of the preparations also change in the dark, though
>a longer time is required. When these preparations are exposed to light
>under a nagetive, the modification of their chemical properties is
>accelerated in such a way that, through the gradations of the tone-values
in
>the negative, the positive print is formed. Now it has been found that we
>also have such accelerators in material substanfces that cfan ber used in
>tghe light,k the process being termed catalysis. It is remarkable that
>these substancfes, called catalyzers, apparently do not take part in the
>process, but bring about merely by their presence, dedomposition or
>combination of other bodies during or upon contact. Hence, catalysis may
be
>defined, in short, as the act of changing or accelerating the speed of the
>chemical reaction by means of agents which appear to remain stable.
>
>Professor Ostwald and Dr. O. Gros of the Leipsic University, have given
tghe
>name of 'catatypy' to the new copying process. The use of light is
entirely
>done away with, except that for the sake of convenience the manipulations
>are executed in the lifht. All that is necessary is to bring paper and
>negative into contact, no matter whether in the light or in the dark.
Hence
>the negative (if necessary a positive may also be employed) need not even
be
>transparent, for the ascending and descending action is produced only by
the
>quantity in the varying density of the silver powder contained in the
>negative. Hence, no photographic (light) picture, but a catatypic picture
>(produced by contact) is created, but the final result is the same.
>
>Catatypy is carried out as follows: Pour dioxide of hydrogen over the
>negative which can be done without any damage to the latter, a lay a piece
>of paper (sized or unsized, rough or smooth, accfording to the effect
>desired); by a contact lasting a few seconds, the paper receives the
>picture, dioxide of hydrogen being destroyed. From a single application
>several prints cfan be made. The acquired picture - still invisible - may
>now in the further course of the process, have a reducing or oxydizing
>action. As picture-producing bodies, the large group of iron salts are
>avbove eminently adapted, but other substances, such as chromium,
manganese,
>etc, as well as pigments with glue solutions may also be employed. the
>development takes place as follows:
>When the paper whidch has been in contact with the negative is drawn
through
>a solution of ferrous oxide, the protoxide is transformed into oxide, hence
>a yellow positive picture results, which can be readily changed into other
>compounds, so that the most varying tones of color can be obtained. With
>the use of pigments, in conjunction with a glue solution, the action is as
>follows: In the places where the picture is, the layer iwth the pigments
>becomes insoluble and all other dye stuffs can be washed off with water.
>
>The chemical inks and reductions, as well as color pigments, of which the
>picture exists, have been carefully tested and are composed of such as are
>known to possess unlimited durability.
>
>After a short contact, simply immerse the picutre in the respective
>solution, wash out, and a permanent picture is obtained."
>
>The is the entire text under the catatypy category. This is very
intriguing
>to me. Does anyone know anything about this?
>
>Dwight
>
>
>
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