Did you know restaurant menus NEVER use blue ink? It is because blue has been shown to decrease the appetite. Think about it. From the Waffle House all the way to the Four Seasons, every shade of bright, vibrant and fresh appears, but blue is a no-no.
in 1842 Sir John Herschel invented the cyanotype, but it was a woman named Anna Atkins who turned it into an art. In one of the most arcane activities I can imagine, and for some curious reason, Dame Atkins decided to collect algae and save them by laying each on light-sensitized paper, creating some 400 images which were published in the first book of photographs. So the very first photograph book was not only published by a woman, it was composed entirely of blue photographs of seaweed. Only 17 copies exist today.
Cyanotypes must be the least expensive photography technique, as the once ubiquitous "blueprints" used by architects and home builders were cyanotypes.
The most extraordinary property of the cyanotype is it's regenerative behavior. Like a starfish with an arm torn off, they come back! They lose their blue easily, but if a faded cyanotype photograph is stored in a dark environment, a good deal of the original color will return like magic. Maybe we should print money in blue?
Untitled (Lumber truck) cyanotype photograph c. 1915 Collection Jim Linderman