The word blueprint is used a lot in the construction field, but it’s really a misnomer. True blueprints were made via an ammonia-based process that created light lines on a dark blue background. They looked like this:
Blueprinting hasn’t been done in about 40 years. It was replaced with blueline prints (also called whiteprints). This was also an ammonia-based process, but it created dark lines on a light blue background. It looked like this:
Both blueprints and blue line prints required a transparent original, which is why Mylar (plastic film) and vellum were used. In the process, a light would shine through the original onto a chemically-coated piece of paper, and you’d get your copy. Blue line printing hasn’t been popular for at least 20 years. But some copy shops still offer it for the few designers that prefer it for presentation purposes.
BTW, do you like that drawing? I did it back in 1983, when I worked as an architect for the Directorate of Engineering and Housing (now called Public Works) at Ft. Sill, Ok. It was for a classroom building I designed for the base. It was built and then, 20 years later, torn down, I hear.
If you want to copy a manually done drawing, you use a large format printer. It digitally scans the drawing and looks like this:
You don’t need an original to make a copy; you can make a copy from a copy, although a film or vellum original will produce the sharpest prints.
Of course, production drawings are all done by computer now, and to-scale hard copies are made on a large printer such as the one below. But if you call them “blueprints,” everyone will know what you’re talking about.
