Cyanotype recipe (4)
Mike Ware's New Cyanotype Recipe
Notes:
1: The following procedure should be carried out under a red safety lamp.
2: This is complicated and time consuming
compared to the Modified Basic Solution. This recipe is VERY light sensitive
with exposures less than one minute in late winter sun! This is too sensitive
for students.
Chemicals
10 g Potassium Ferricyanide
30 g of Ammonium Iron (III) Oxalate
0.5 ml 25% Ammonium Dichromate solution
distilled water
Procedure
1) Using a mortar and pestle, finely powder 10 g Potassium Ferricyanide until no red crystals remain.
Wear a dust mask to avoid inhalation of the toxic powder.
2) Heat 30 ml distilled water to 50° C and dissolve in it 30 g of Ammonium Iron (III) Oxalate.
3) Add 0.5 ml 25% Ammonium Dichromate solution to the above solution and mix.
4) While the solution is still hot add 10 g of powdered Potassium Ferricyanide in small proportions while stirring vigorously. Green crystals should begin to appear. Set the solution aside for an hour to crystallize.
5) Separate most of the liquid for the green crystals by filtration. The green solid, Potassium Iron (III) Oxalate, should be disposed of safely. The volume of the collected solution is about 30 ml.
6) Make up the olive-yellow colored solution with distilled water to a final volume of 100 ml.