Re: bleach/etch or mordancage

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From: Randall Webb (randall.webb@lineone.net)
Date: 03/22/01-08:37:26 PM Z


----- Original Message -----
From: Christina Z. Anderson <tracez@mcn.net>
To: Alt Photo List <alt-photo-process-l@skyway.usask.ca>
Sent: Wednesday, March 21, 2001 9:17 AM
Subject: bleach/etch or mordancage

> I think the original poster about this topic, about a year or so ago, was
> Jonathan Bailey. Then there was a remention in the last couple months,
> where Judy S. said that bleach/etch and mordancage were the same process.
> Anyway, in rereading the posts I saw that Jonathan was interested in
> anything in print on this topic. I have come across, in researching other
> stuff, two mentions of it. One is in Ilford Monochrome Darkroom Practice
by
> Jack Coote, pp. 299-304. The other was an article in Shutterbug called
> Bleach Etch by Frances Schultz, oct 1998, pp. 30-36. I've had it in my
file
> of alt processes since then--sometimes when you file things you never find
> them! If the list is interested I can condense the info into a post.
> The formula in the Ilford manual is 30g copper chloride, 100 ml of
> acetic acid 80%, and water to make 1000ml, with an added hydrogen peroxide
> 20vol just prior to use. The Shutterbug article calls Hydrogen Peroxide
> 20vol equivalent to 6%. Is this correct? The Shutterbug formula only has
> 80ml of the glacial acetic acid, but otherwise is the same (oh--is 100ml
80%
> acetic acid equiv to 80ml glacial acetic? If so, the two formulae are
> identical)(can you tell I didn't take chemistry?) These two formulae
differ
> quite a bit in measure from Jonathan's, but not in content.
> Chris>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

You will find bletch-etch process covered at great length in "Spirits of
Salts " ( all of two pages). Two pages is about twice as much as it is
worth! From an old process point of view it is more of a curiosity and more
of an alt. process. More about this distinction at a later date. It was used
industrially for making small amounts of display cards and exhibition
publicity material without the bother of making printing plates and the use
of printing presses. One of the best gelatin silver printers in UK (his
words not mine!) spent 10 years when he was young working with it. He says
he still wakes up in the night with the stench of it in his nostrils.
Kentmere in UK used to make a special paper for it with a soluble coating,
pre-prepared chemicals and a range of vegetable dyes.
Now you have to make your own etch solution, use dyes for colouring cake
icing and for paper you must use standard crap resin coated paper. If
anybody wants to display a print on disgusting resin paper then thats your
problem.
The best way to do it is to make a bleach etch on resin, scan it and print
it on inkjet pseudo art paper.
As far as mordancage is concerned I have no idea. It sounds like some
mediaeval torture technique to me. I shall have to ask Judy. (No about
torture but printmaking!!!!!!!!!)
Randall Webb


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