More About Blueprints

Blueprints were first developed by John Herschel, a chemist, astronomer, and photographer in 1842.
The process begins with a drawn image on semi-transparent paper on top of a sheet of paper or cloth. The paper or cloth is pre-coated with a photosensitive mixture of chemicals, which when exposed to light turn blue. In this process, the lines on the drawing block the light from hitting the chemicals leaving these lines white while the background is turned blue – hence the term, blueprint.

Blueprinting was originally invented as an inexpensive way to make copies of notes and drawings. With its introduction in the late 1800’s American architectural offices found method of reproducing architectural drawing to be one tenth of the cost of hand traced reproduction. The speed with which copies could be made was also greatly increased. As a result it gained widespread commercial use in this field.
As technology advanced the printing and copying process, the old method of blueprinting has been replaced by even more advanced and efficient ways of producing architectural drawings, but the term “blueprint” continues to be commonly used to identify architectural drawings as well as drawings in other fields.