The
Kallitype Photographic Process - A Short Introduction by Christopher
John Ball
The
Kallitype is another process that uses ferric salts with silver nitrate
and produces a brown-tone image. It was introduced by Dr. W. J. Nichol
in 1899 and was based on Herschel's argentotype (1842). It is similar
in appearance to a platinotype but is formed of a metallic silver
instead of platinum.
Formula
one:
The
three part solution is below. After the individual solutions have
dissolved, combine A and B then slowly add C while stirring constantly.
This solution has a shelf life of about 2 years if stored in a brown
bottle in a dark place. With age, the prints will yield richer brown
tones.
Part A:
Distilled water 33ml
Ferric ammonium citrate 9g
Part B:
Distilled water 33ml
Tartaric acid 1.5g
Part C:
Distilled water 33ml
Silver nitrate 3.8g
Expose
the sensitised paper in contact with the chosen negative to sunlight
or UV light. Exposure can be anywhere from 2 minutes to an hour. Develop
in running water for one minute then fix in a hardening fixer diluted
1:16 for five minutes. The image will darken as the image becomes
permanent. Wash as a normal print for about 40 minutes and dry.
Formula
two:
Part
A:
Ferric Oxalate 112g
Potassium Oxalate 28g
Silver Nitrate 28g
Water to make 500ml.
Coat
the paper with the above solution. When dry, place the negative in
contact with the emulsion/paper and expose in a UV source until only
the shadows are visible. Then develop the print in the following solution;
Part
B:
Borax 25g
Sodium Potassium Tartrate (Rochelle Salt) 30g
Water to make 500ml
Use
a ferric ammonium citrate sensitiser, and development in water, produced
warm sepia tones.
The
print is fixed in a 3% sodium thiosulphate solution, made slightly
alkaline with ammonia.
Formula
for American Kallitype:
Based
upon the Jas Thomson process and consists of a separate salting and
sensitising solutions.
Salting
Solution:
Ferric-ammonio Citrate 45g
Ferric Oxalate 27g
Potassium Oxalate 27g
Copper Chloride 13.5g
Oxalic Acid 9g
Gum Arabic 23g
Distilled Water 1litre.
Coat
the paper with the above formula. If you would like a more velvety
tone then size the paper first. Once dry treat the paper with the
following solution:
Sensitiser:
Oxalic Acid 5g
Citric Acid 45g
Silver Nitrate 113g
Water 1litre.
When
dry, place the negative to be printed in contact with the paper and
expose to a UV light source. A starting exposure of about 4 minutes
should be adequate. The image will look brownish on a yellow background.
Stop the exposure before the half tones appear. Develop the print
in running water for about 3 minutes. After washing, fix in a weak
hypo solution. After a final wash of about 1/2 an hour hang the print
to air dry.
Various
Tones are possible via substituting one of the following developing
formulae:
For
Black Tones:-
Borax
110g
Sodium Potassium Tartrate 83g
Potassium Bichromate (1% solution) 115ml
Water 1litre.
For
Sepia Tones:-
Sodium
Potassium Tartrate 55g
Potassium Bichromate (1% solution) 70ml
Water 1 litre.
For
Purple Tones:-
Borax
30g
Sodium Potassium Tartrate 110g
Potassium Bichromate (1% solution) 115ml
Water 1 litre
For
Maroon Tones:-
Sodium
Potassium Tartrate 110g
Sodium Tungstate 55g
Water 1 litre.
The
print is developed in one of the formulae for between 15 and 30 minutes.
Although the image may appear quickly, the print must remain in the
solution for the time stated so as to render the iron salts soluble.
The print is then put, without washing, into the following fixer for
about 10 minutes:
Sodium
Hyposulphite 55g
Liquor ammonia 13ml
Water 1 litre.
Wash
the finished print in water for about 20 minutes.
After
Treatment:
Kallitype
prints can be treated in many of the same ways as conventional monochrome
prints in so far as they can be toned, reduced, re-developed and intensified.
Over-exposed
prints can be reduced by placing in a weak solution of hydrobromic
acid for about 3 minutes followed by washing for 30 minutes Another
method is to immerse the print in the solution for a few seconds and
then place in a weak hypo fixing bath followed by washing. This method
increases contrast considerably and can be used to get good prints
from weak negatives.
To
intensify a kallitype use the same methods as for Bromide.
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