California has more architects than any other state with 17,241 architects as of 2016. The state with the second-most, New York, has 10,734. One type of paper that virtually all engineering and architect firms use and work with on a regular basis is blueprint paper. Blueprints are ideal for technical drawings involving specific measurements, but did you know that they've been in existence since the 1800s? Blueprints have a surprisingly fascinating history -- here are just a few interesting points about the history of blueprint paper.
Alphonse Louis Poitevin
Alphonse Louis Poitevin was a French chemist who first found that the ferro-gallate in acacia gum is sensitive to light exposure. From there, he discerned that light turns the gum into a shade of blue that's insoluble and permanent. This means that when coated onto paper or another bases, an image from a translucent document can be reproduced.
Furthermore, the ferro-gallate is then coated on to another paper made from an aqueous solution and then dried. The coating is actually yellow, and in total darkness, it is considered to be 'stable' for a maximum period of three days. Then, the paper is secured underneath panels of glass in addition to a light transmitting document.
The Cyanotype Process
There are other processes for making blueprints that are carried out using photosensitive ferric compounds. One of the most well-known processes is called cyanotype. It uses ammonium ferric citrate and potassium ferricyanide to create a bright blue compound.
"Using the cyanotype process, an architectural drawing was made on a semi-transparent paper, then weighted down on top of a sheet of paper or cloth that was coated with a photosensitive chemical mixture of potassium ferricyanide and ferric ammonium citrate. In the final stages, the document was exposed to light. The exposed parts of the drawing (the background) became blue, while the drawing lines blocked the coated paper from exposure and remained white," writes PlanGrid.
Ultimately, understanding how blueprints are made is an interesting and insightful look into how far the paper industry has come. For more information about 36 inch paper rolls or engineering bond paper in bulk, contact Get Paper.