Cyanotype Blueprints Honesty Commentary

John Herschel chemistry

Cyanotype

The initial preparation of potassium ferricyanide and ferric ammonium citrate, when dried on paper, is photosensitive. Expose this to ultraviolet light shown through a mask, then rinse off the paper. Only areas exposed to light retain the Prussian blue.

Blueprints

Mechanical and architectural drawings are still called blueprints even though they are printed black on white. Same idea. Unlimited copies of a complex master drawing for engineers and construction workers at exactly the same scale as the original.

Honesty

Democracy thrives in sunshine. Honesty shines through tinted lenses. You may have any color so long as it’s blue.