Friday , 17 November 2017

Base Formulas for Cyanotype

The chemicals needed for cyanotypes are inexpensive. They are relatively safe to handle and keep well both dry and in solution.

Ferric ammonium citrate: Two powdered forms: 1.) brown-red and 2.) green. The green powder is more light sensitive and produces a longer tonal range.

Potassium ferricyanide: Exercise care. There is a similar compound, potassium ferrocyanide, that will not work for the cyanotype process.

Getting Started:

1.) Pick a base formula. (below)

2.) Mix distilled water with ferric ammonium citrate (green) in a light-safe bottle.

3.) Mix distilled water with potassium ferricyanide in a light-safe bottle.

4.) Label one bottle “Solution A” and the other “Solution B.”

Storage:

Store both of these solutions in glass or plastic light-safe bottles, keeping them out of extended light or heat.

Special consideration should be given to time. Eventually, the ammonium citrate solution will grow a fungus that floats on the surface. This does not affect its usefulness, but the fungus should be strained through a coffee filter or cheesecloth before you coat the paper.

 

BASE FORMULA #1

Ferric Ammonium Citrate 10g Solution A
Distilled Water 100ml
 
Potassium Ferricyanide 8g Solution B
Distilled Water 100ml

Formula 1: One version of Sir John Frederick William Herschel’s 1842 original process.

 

BASE FORMULA #2

Ferric Ammonium Citrate 20g Solution A
Distilled Water 100ml
 
Potassium Ferricyanide 16g Solution B
Distilled Water 100ml

Formula 2: Variation of Herschel’s original process with double the concentration.

 

BASE FORMULA #3

Ferric Ammonium Citrate 36g Solution A
Distilled Water 100ml
 
Potassium Ferricyanide 20g Solution B
Distilled Water 100ml

Formula 3: Highly concentrated, modern variation of the original formula.

 

BASE FORMULA #4

Ferric Ammonium Citrate 13.5g Solution A
Distilled Water 100ml
 
Potassium Ferricyanide 4.5g Solution B
Oxalic Acid .5g
Ammonium Dichromate .1g
Distilled Water 100ml

Formula 4: Dick Sullivan’s personalized cyanotype formula.

 

BASE FORMULA #5

Ferric Ammonium Citrate 27g Solution A
Oxalic Acid .5g
Distilled Water 100ml
 
Potassium Ferricyanide 9g Solution B
Oxalic Acid .5g
Ammonium Dichromate .2g
Distilled Water 100ml

Formula 5: Unique and highly complex modern formula.

 

Ready to print?

Review the cyanotype process, step-by-step.

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