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t32.txt
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1980-06-03
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Etch bleach is a very specific type of process, and the results
can be impressive, or boring if overdone. The end picture really
does depend on your imagination. The method is set out below....
THE ETCH BLEACH PROCESS
The Etch Bleach process is a useful and versatile tool for
the keen monochrome worker. First, a broad description. A
monochrome print is produced on a glossy, resin coated
paper. It must be a resin coated paper for the method to
work.
The print is finished to a dry state as usual, as the etch
bleaching can be done at any time and in daylight.
Subject matter is best kept simple as the process does not
take kindly to masses of detail. Experience will show the
best type of print to use - it is quite feasable to print a
slide, producing a negative print to start on !!
The print is immersed in the etch bleach solution, which
literally removes all the emulsion which was darker than a
certain shade of grey. That lighter than that shade will
remain on the print.
The print is swabbed with cotton wool to remove any loose
material, and the print washed - and dried for later if
desired.
The next stage can be to re-develop the print in any print
developer. Any tones remaining will return usually along
with a sabbatier line effect. (The sabbatier effect is
normally a result of a process called `solarisation` when
the subject finishes up outlined in a black line.) The print
should then be fixed. It should also be fixed if no
re-development took place. All of this can be in full light.
The print can then be immersed in any dye - Dylon is good
- and washed briefly. The result is a coloured picture
where emulsion remained, but pure white elsewhere as only
the water proof coating, which wouldn`t absorb dye, would
remain. It is best to swab the print dry with kitchen roll
or similar as the emulsion will will easily scratch at this
stage.
The resulting picture can be very impressive indeed, but
does depend very much on the original choice of subject.
Light areas on the original will be light on the final
print. Thus a print from a transparency will finish as a
positive etch bleach. i.e. A sky will print black, and the
etch solution will remove all blacks. The sky will thus be
a clear white on the final picture.
Colours can be mixed, or selective dying can be attempted
using swabs, or blocking out with rubber solution. The end
product depends entirely on the imagination.
MORE DETAILED METHOD.
Select your slide or negative and produce a strong print
with good blacks and whites. Finish it in the normal way
to a dry picture. Any of the resin coated papers appear to
work, including the variable contrast types, which allow
better contrast control.
The etch bleach solution cannot be bought, so you have to
make it up yourself, or get a chemist to do it for you.
All the chemicals are available from chemists although some
may need to be ordered.
The chemicals consist of two separate solutions which
should only be mixed together just before use. ( The A and
B solutions can be made up at any time and keep
indefinately. )
SOLUTION A
Copper Sulphate 60 Grammes.
Citric Acid 75 Grammes.
Potassium Bromide 4 Grammes
Water to a total of... 500 ccs.
SOLUTION B
Hydrogen Peroxide 20 Vol. Strength.
(This is available at this strength directly from chemists -
it`s used as a hair bleach. )
Always mix chemicals in the order given. Make sure each
chemical is fully dissolved before adding the next and use
warm water to aid dissolving. Treat all chemicals with
respect.( Potassium Bromide is what is reputed to have been
put in soldiers tea to keep their mind off the opposite
sex ! ) None of the above are really dangerous but don`t
lick fingers and always wash hands and the work area when
finished. I store the made up solutions in re-labelled and
washed developer and fixer bottles.
Mix equal parts of A and B just before use, and if your skin
is a bit sensitive, use rubber gloves. Hydrogen Peroxide
can be an irritant.
Warm the solution to a MINIMUM of 50 deg. C. It only works
when at that sort of temperature. I use an old cooking basin
to warm it over the gas ring as it is usually necessary to
re - warm it during the session.
Wet the print to be bleached using warm water, to retain
temperatures, and immerse it in the bleach. In a few seconds
the image will disappear. Using a cotton wool swab, wipe the
print surface whilst it is still in the bleach. If all is
well, areas of the emulsion will be seen coming off looking
much like frogspawn !
Remove the print and rinse in warm water. Continue swabbing
GENTLY until no more emulsion comes off. At this point
there are various possibilities. It can be dried and stored
for another day if desired.
To prepare the final image, and if it is to be just colour,
fix the print. If some detail is required, then make sure
that the bleached print is well exposed to light and immerse
in a normal print developer. Tonal areas remaining will
re-develop. When no further action takes place, wash and fix
the print.
This stage could be an end product as it can look quite
impressive. I have, on occasions, re-photographed the
print at this point to produce a master negative for future
use.
To add colour, take the fixed and dried print and place it
in a suitable dye. All the emulsion that remains will
take on that colour. Areas stripped of emulsion will remain
white. Remove the print from the dye and rinse briefly.
Swab to clear the white areas and dry your masterpiece.