Through the years, we have seen several authentic blueprints come through our doors. Time and time again team members are just as fascinated with them. Blueprints are truly pieces of history and paved the way to the modern processes of reproduction we have today.
By definition a blueprint is a type of paper-based reproduction usually of a technical drawing, documenting architecture or engineering designs. As print and display technology has advanced, the traditional term “blueprint” has continued to be used informally to refer to any detailed plan even though actual blueprints are no longer made.
John Herschel, who was a chemist, astronomer, and photographer, developed the process for blueprints in 1842. Herschel had discovered the cyanotype process after a series of experiments. The process starts by taking a drawn image on semi-transparent paper weighed down on top of a sheet of paper or cloth. The paper or cloth is pre-coated with a photosensitive chemical mixture of potassium ferricyanide and ferric ammonium citrate. Once the drawing is 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.
Introduction of the blueprint process eliminated the expense of photo lithographic reproduction and the need to hand-trace original drawings. By the 1890s in American architectural offices, a blueprint was one-tenth the cost of a hand-traced reproduction and could be copied in a lot less time.While the cyanotype process was intended to be a means of reproducing notes and drawings, it gained widespread commercial use.
The process grew popular among scientists, artists, and photographers as it was a relativity cheap and simple way to reproduce images. It was also used to preserve the silhouette of leaves, ferns, and other samples used in botanical illustrations.
Beyond the Blueprint
In the 1940’s the cyanotype blueprint became substituted by diazo prints, or whiteprints. These prints have blue lines on a white background. These drawings were also called blue-lines or bluelines. The diazo print still remains in use in some applications but for the most part has been replaced by modern reprographic methods of printing and copying.
While original drawings in the 19th century were hand drawn on linen or vellum, today’s original drawings are mainly digital files created using Computer-Aided Design (CAD). The need for copying original drawings has declined as the originals are no longer hard copies. CAD files can be sent directly from computer to plotter as a means of reproduction. In some cases paper is avoided altogether, and work and analysis is done directly from digital files.
Today’s print processes are similar to standard copy machine technology that uses toner and bond paper. In addition, the use of large-format scanners serves as a modern method of copying. Digitizing an image now allows architects and engineers to work from digital displays rather than a hard copy. The scan of the drawing can also be printed almost immediately after the image is created.
Again, with the introduction of CAD, paper copies and prints may be avoided altogether. Display technologies continue to advance to benefit the modern construction and architecture firms. Viewing and sharing plans digitally is the latest trend in the industry. Software companies such as PlanGrid or BlueBeam specialize in this technology allowing firms to view plans from the various mobile devices that exist today.
Don’t’ forget that here at Avalon, we can handle it all. If you have old blueprints you would like reproduced, whether copied or scanned, we can help. Even if they are a little rough around the edges we will take our time and make sure your original blueprints remain in the same condition as you brought them to us. If you have a PDF drawing or hard copy print, we can print, copy and scan those too!
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