July 9, 2020
Blueprints and Cyanotypes at Home!
Use the sun to make your own blueprints and cyanotypes
Have you ever wondered how people made copies of important drawings and documents before copy machines? There have been many different inventions over the years to help make copies of things, from pantographs to carbon paper copy books. These are examples of different methods of mechanically tracing or making a copy of something while you're writing it. We have examples of both in our collection at HMM, but those are artifacts for another day. Instead, today we want to investigate a process that has more in common with photography than with tracing: blueprinting!
How does blueprinting work?
First, a piece of paper is treated with chemicals that turn blue in the sun. The original document is stacked on top of the blueprint paper and left in the sun for a while. The sun shines through the blank parts of the drawings and turns the paper underneath blue. The ink on the original drawing works like sunscreen, blocking the sun and keeping the paper white underneath the inked part of the drawing. This is why a blueprint of a simple line drawing is mostly blue, and the lines of the drawing in a blueprint are white.
Blueprinting vs. Cyanotypes
In addition to copying documents, paper treated with the same chemicals can be used to make beautiful prints. These are called cyanotypes, while blueprints are usually prints of technical drawings. Cyanotypes are made from photo negatives or use natural items like leaves and flowers. Both cyanotypes and blueprints became popular in the mid 1800s. The Herreshoff Manufacturing Company made many blueprints of their own drawings. This way, they could use them in the shops without ruining the original drawings. People used cyanotypes for scientific and artistic purposes too in the 1800s. Herreshoff family members took many photos, and Captain Nat's daughter Agnes printed many of her negatives as cyanotypes.
Today you can still buy blueprint paper! It's usually marked as "sunprint paper" or "sun sensitive paper." Try ordering a small pack online and following the instructions to make your own. Experiment with photo negatives, flowers, leaves, dried seaweed or your own drawings to make prints yourself. You can also order the solutions to make your own blueprint/cyanotype paper at home!
And if you want to get really advanced, you can try mixing and printing your own cyanotype photos like Agnes - try this mix-your-own kit and tutorial: