Cor Breukel's Adaption

Cor Breukel's Adaption of the Copper Printing method

5/17/2004

Due to copyright limitations, this page is a paraphrase of the published text.
From p39, 52-53 of Issue #9 of "The World Journal Of Post-Factory Photography" [also, sadly, the last issue]
See web site at the Unblinking Eye

PAPER

Use a paper with some 'tooth' to it, so the agar sizing will adhere. Hot press papers will tend to 'blister'.

Use a 1% agar solution. You must bring the water to a boil in order to dissolve the agar. Pour agar solution into a pyrex baking dish larger than the paper you want to use. It helps if this dish is in a bigger dish of near boiling water to prevent the agar from setting up. Float the paper on the agar and allow to sit for a few seconds. Then lift by one corner in one even motion [to prevent bubbles]. Blot off excess agar and let dry vertically. Agar can be stored in a bottle in the fridge. Microwave to remelt [cpatton's additional tip].

CHEMISTRY

Solution A:

to 20 ml of distilled or deionized water add:
5.0 grams sodium citrate
5.0 grams sodium acetate
2.5 grams copper sulfate
let cool before use. May be stored in a dark brown bottle in a cool dark place

Solution B:

to 20 ml of distilled or deionized water add:
2 grams of potassium ferricyande

Solution C:

to 10 ml of distilled or deionized water add:
5 grams of ammonium persulfate [Potassium persultate may be used instead]

IN THE DARK [yellow bug light works well here, or normal darkroom safelight]

adding A&B will result in a light sensitive solution, so only do so just before use. Stocks may keep [cpatton note: solution C is the least stable, if you have problems, remake C first]. Solution C helps with the highlights.

the emulsion is mixed in this ratio A:B:C = 1:1:0.1 JUST BEFORE USE as a percipitate will form.
Solution C must be added with rigorous stirring. Upon standing a precipitate will form again.

For every single coat the emulsion must be made fresh. A bit of a
nuisance, but mixing the stocks is rather quick. Apply 2 coats for best results.

Cor recommends a foam brush and letting the emulsion dry between coats. May use a cold air stream to help. NO HEAT.

Coated paper MUST be DRY before coming into contact with a negative or the ferricyanide will ruin the negative.

EXPOSURE

The negative should not be too dense or pyro stained. A normal negative works fine.

Expose to UV light source or sunlight. Exposures are longer than with a cyanotype. POP, so can inspect at intervals to see how things are going. There is intensification upon 'developing' and Amidol treatment.

DEVELOPMENT

float face down in a try of water for one minute. Then carefully transfere to fresh water bath and carefully and gently wash for 2-3 minutes. May be hung to dry at this point or intensified in Amidol

AMIDOL INTENSIFICATION

For an 8x10 print you need about 125 ml of the amidol solution. The solution
will not keep, and has to be made fresh and is used single shot.

125 ml water [does not need to be distilled]
2.5 grams citric acid
0.1 grams Amidol

pour over print and agitate for about 30 sec.

wash 2-3 times with washes of fresh water [BE GENTLE]

Blot dry and dry completely with HEAT. a hot hair dryer, dry mount press [microwave?]. Heat brings out more color.

Exact color will vary with emulsion coatins, paper, agar sizing, etc.

SAMPLE IMAGES: