When ferric ammonium citrate or ferric ammonium oxalate is mixed with potassium ferricyanide, it becomes sensitive to UV light. These chemicals can be painted onto paper or fabric and left to dry in a dark room. Once dry, objects can be arranged on the paper and placed in the sun.
The UV rays from the sun react with the chemicals and where the print has been covered with an object it will remain white. Once the chemicals are rinsed off with water, fixing the print so it is no longer sensitive to the sun, you are left with a blue and white print.
For details, see Instructions.
For more images and videos, visit Cyanoblueprints on Instagram
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