1842

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.