From: Peter Marshall (petermarshall@cix.co.uk)
Date: 11/27/01-03:58:21 PM Z
At last a hunt through the bottom drawer of my filing cabinet at work
revealed the following article on etch bleach using a copper sulphate
based bleach.
All prints bright and beautiful
BY ALAN McFADEN
Amateur Photographer, June 16 1976
He suggests starting with a negative print and gives the following copper
bleach formula using copper sulphate:
A
Warm water 1500cc
copper sulphate 240g
citric acid 300g
potassium bromide 15g
Make to 2 litres
B
20 vol hydrogen peroxide
Use equal parts of A and B at 80-90F
There isn't much more of interest in the article, but it did provide a
starting point for many further experiments by myself and my students. I
was surprised to find it was twenty five years ago.
I don't think I bothered to use the formula - just went into the chemistry
lab and took copper sulphate, potassium bromide etc bottles of the shelf
and made a rough mix.
We used to dilute 100 vol hydrogen peroxide for B.
Peter Marshall
petermarshall@cix.co.uk +44 (0)1784 456474
31 Budebury Rd, STAINES, Middx, TW18 2AZ, UK
_________________________________________________________________
London's Industrial Heritage: http://petermarshallphotos.co.uk/
The Buildings of London etc: http://londonphotographs.co.uk/
Also on Fixing Shadows: http://www.people.virginia.edu/~ds8s
and elsewhere......
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