Why Blueprints Are Blue
Whyareblueprintsblueand not some other color? There's a specific chemical process behind it, and its discovery has all the elements of a dark fairy tale. Blueprintsarean older style of drawing that is now totally obsolete. They were used because scientists had discovered a certain type of chemical that turnedblueafter it had been exposed to air.
Ablueprintis a paper-based reproduction of a technical drawing, such as an architectural plan or an engineering design, historically used to create accurate copies of original documents. The term itself refers directly to the distinctive white-on-blueappearance that characterized these reproductions for over a century. Blueprintsarebluedue to the cyanotype process, invented in 1842.
The chemical reaction uses UV light to create the stable, insoluble Prussianbluepigment. Whyareblueprintsno longerblue? Learn about how the process of creating architectural documents has evolved since the 19th century. Before PDFs, digital submittals, and cloud-based plan portals, we had real blueprints—chemically treated sheets that turned deepbluewith white lines.
Anyone who's been in this business long enough remembers the smell of ammonia from a diazo machine or the feel of those oversized, curled-up... Whereasblueprintreproductions are negatives of an original drawing, the diazo (whiteprinting) process provides positive images like those ofblue-line prints, except the lines can be of almost any color on a white background. The paper is coated with a diazo compound that is sensitive to ultraviolet light.
Whyareblueprintsblueinstead of yellow?Blueprintsarebluebecause of the specific chemical process used to create them, known as cyanotype, which was invented in the 19th century. This process uses a mixture of ammonium iron citrate and potassium ferricyanide, which reacts to ultraviolet light to create a deep Prussianbluepigment. The answer is simple but important.
Thebluecame from Prussianblue, the pigment-like compound formed during the cyanotype reaction. This gaveblueprintstheir distinctive appearance and their name. That is alsowhythe termblueprintbecame so powerful in the language.
It described both the image color and, eventually, the idea of a detailed ... IntroductionBlueprintshave been an indispensable part of architectural and engineering workflows for over a century. Their distinctivebluebackground paired with white technical lines is familiar to many, but the reasons behind this iconic appearance are both historical and chemical.
Theblueprintprocess revolutionized how detailed designs and technical drawings were copied, making it a ...
