TIL Why We Call Schematics ‘Blueprints’
Engineers and Architects use and create plans known as blueprints when they are normally just drawings on white paper, so why is that?
In 1861 a French chemist discovered that ferro-gallate was light sensitive. Other scientists later found that an ammonium iron citrate and potassium ferrocyanide solution reacts the same way. When paper is coated with these substances, dried, and then exposed to light, the paper turns blue.
The advantage of this process was soon evident in being able to quickly reproduce documents.
The image that is to be copied is drawn onto translucent tracing paper with a dark India ink. That tracing paper is secured over paper prepared with the photosensitive solution and exposed to UV light for a few minutes. When complete, it is taken out of the light and you have a blue document except where the dark lines of ink blocked the sun, those remain the color of the paper (usually white).
To stop any future UV light from changing the remaining un-blued lines, the solution is washed off the paper, which is then allowed to dry. This process also makes it very difficult to alter the document, usually a good thing.
This process was about 90% cheaper and resulted in duplicates that were made much faster and contained less errors than hand copying everything. This enabled ‘blueprinting’ to become so widespread that the name for such a document remained even after the process fell from common use in the middle of the 20th century, although most in the industries just call such modern day copies “prints” or “drawings”.
Today they have become a sort of engineering art. I have found a small assortment of blueprints, some real - some created as artwork.
1875 Colt Peacemaker
Sydney Opera House
Wright Brothers 1903 Flyer
Chrysler Building
German U-Boat
Brooklyn Bridge
Ford Model-T
Titanic
Sources:
In 1861 a French chemist discovered that ferro-gallate was light sensitive. Other scientists later found that an ammonium iron citrate and potassium ferrocyanide solution reacts the same way. When paper is coated with these substances, dried, and then exposed to light, the paper turns blue.
The advantage of this process was soon evident in being able to quickly reproduce documents.
The image that is to be copied is drawn onto translucent tracing paper with a dark India ink. That tracing paper is secured over paper prepared with the photosensitive solution and exposed to UV light for a few minutes. When complete, it is taken out of the light and you have a blue document except where the dark lines of ink blocked the sun, those remain the color of the paper (usually white).
To stop any future UV light from changing the remaining un-blued lines, the solution is washed off the paper, which is then allowed to dry. This process also makes it very difficult to alter the document, usually a good thing.
This process was about 90% cheaper and resulted in duplicates that were made much faster and contained less errors than hand copying everything. This enabled ‘blueprinting’ to become so widespread that the name for such a document remained even after the process fell from common use in the middle of the 20th century, although most in the industries just call such modern day copies “prints” or “drawings”.
Today they have become a sort of engineering art. I have found a small assortment of blueprints, some real - some created as artwork.
1875 Colt Peacemaker
Sydney Opera House
Wright Brothers 1903 Flyer
Chrysler Building
German U-Boat
Brooklyn Bridge
Ford Model-T
It is the same chemical process I use to make my cyanotype art. There are examples of the process on my blog.
The art world is keeping the process alive! :D
Fantastic stuff, bro! Love the examples you've provided too! And you're absolutely right, they can be seen as works of art with all the details and intricacies. Well done yet again! :)
You could get a local blueprint for your flat!
And it is such a pretty blue.
The blue print had a very short life. Then came blue line (ammonia developed). Which was around for a mere 30 years before plotters came along. And now, it is just easier to print another set of plans then to use any of these old copying techniques.
Well, blueprints started giving way to blue lines called 'whiteprints' around the 1940's, 90 years is a decent run (1861-1940's). Heck, it is getting more common that there are no printed schematics and everyone is just using pdf files on their iPads and such. :D
It has resurfaced as a boutique niche of art, but I am unsure if they use the old process or just print it with blue ink.
I am pretty sure that the new stuff is printed with blue ink.
An actual blueprint has a feel, a fuzzyness of edge of line, its paper is thick, etc.
The paper had to undergo being washed. We just don't have that kind of paper any more. (Well, you can go buy artists paper, like specifically for watercolors).
If you get your hands (or just eyes) on a real blue print, it just has so much more depth in it.
The prints I have seen in stores are printed.
Yea, that was my guess but I hadn't seen an actual one with my own eyes.
Nice article!
Similar chemicals were used to make the famous Prussian Blue ink.
Yea! The blue of original schematics was named Prussian Blue, prized for its ability to resist fading. :)
You inspired me to write an article on toning black & white photos.
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