Blueprint

Blueprint (pronounced bloo-print)

(1) A process of photographic printing, used chiefly in copying architectural and mechanical drawings, which produces a white line on a blue background; also called a cyanotype.

(2) A physical print made by this process.

(3) A slang term for a digital rendition of the process.

(4) A slang term for such a drawing, whether blue or not.

(5) By analogy, a detailed outline or plan of action (in text or image).

(6) To make a blueprint.

(7) A technique for optimizing the performance of internal combustion engines by machining (or matching) components to their exact specifications.

1887: The construct was blue + print (blue print and blue-print (1882) were the rarely used alternative spellings).  The figurative sense of "detailed plan" dates from 1926 and use as a verb is from 1939.

Blue dates from the sixteenth century and was from the Middle English blewe, from the Anglo-Norman blew (blue), from the Frankish blāu (blue) (possibly via the Medieval Latin blāvus & blāvius (blue)), from the Proto-Germanic blēwaz (blue, dark blue), from the primitive Indo-European bhlēw (yellow, blond, grey).  It was cognate with the dialectal English blow (blue), the Scots blue, blew (blue), the North Frisian bla & blö (blue), the Saterland Frisian blau (blue), the Dutch blauw (blue), the German blau (blue), the Danish, Norwegian & Swedish blå (blue), the Icelandic blár (blue).  It was cognate also with the obsolete Middle English blee (color) related to the Welsh lliw (color), the Latin flāvus (yellow) and the Middle Irish blá (yellow). A doublet of blae.  The present spelling in English has existed since the sixteenth century and was common by circa 1700.  Many colors have in English been productive in many senses and blue has contributed to many phrases in fields as diverse as mental health (depression, sadness), semiotics (coolness in temperature), popular music (the blues), social conservatism (blue stocking; blue rinse), politics (conservative (Tory) & Whig identifiers and (unrelated) the US Democratic Party), labor-market segmentation (blue-collar), social class (blue-blood), stock market status (blue-chip) and, inexplicably, as an intensifier (blue murder).

Print dates from circa 1300 and was from the Middle English printen, prenten, preenten & prente (impression, mark made by impression upon a surface), an apheretic form of emprinten & enprinten (to impress; imprint).  It was related to the Dutch prenten (to imprint), the Middle Low German prenten (to print; write), the Danish prente (to print), the Swedish prenta (to write German letters).  The late Old French preinte (impression) was a noun use of the feminine past participle of preindre (to press, crush), altered from prembre, from the Latin premere (to press, hold fast, cover, crowd, compress), from the primitive Indo-European root per- (to strike).  The Old French word was also the source of the Middle Dutch (prente (the Dutch prent) and was borrowed by other Germanic languages.

The sense of "a printed publication" (applied later particularly to newspapers) was from the 1560s.  The meaning "printed lettering" is from the 1620s and print-hand (print-like handwriting) from the 1650s.  The sense of "picture or design from a block or plate" dates from the 1660s while the meaning "piece of printed cloth or fabric" appeared first in 1756.  The photographic sense emerged apparently only by 1853, some three decades after the first photographs, the use evolving as printed photographs became mass-market consumer products.  Print journalism seemed to have been described as such only from 1962, a form of differentiation from the work of those employed by television broadcasters.

Blueprinting internal combustion engines is the practice of disassembling the unit and machining the critical components (piston, conrods etc) to the point where they exactly meet the stated specifications (dimensions & weight).  Essentially, the process is one of exactitude, using precision tools to make components produced using the techniques of mass production (which inherently involves wider tolerances) and modifying them by using tighter tolerances, meeting exact design specifications.  It’s most associated with high-performance racing cars, especially those which compete in “standard-production” classes which don’t permit modifications to most components.  In some cases, especially with factory-supported operations, the components might be specially selected, prior to assembly.

Blueprint of the USS Missouri (BB-63), an Iowa-class battleship launched in 1944.  Missouri was the last battleship commissioned by the US Navy.

The first blueprint was developed in 1842 by English mathematician, astronomer, chemist & experimental photographer Sir John Herschel (1792-1871).  What he then termed a “cyanotype process” eliminated the need to copy original drawings by means of hand-tracing, a cumbersome, time consuming (and therefore expensive) process.  At what was then an astonishingly low cost, it permitted the rapid and accurate production of an unlimited number of copies.  The cyanotype process used a drawing on semi-transparent paper that was weighted down on top of a sheet of paper which was then placed over another piece of paper, coated with a mix of ammonium iron citrate and potassium ferrocyanide (derived from an aqueous solution and latter dried).  When the two papers were exposed to light, the chemical reaction produced an insoluble blue compound called blue ferric ferrocyanide (which became famous as Prussian Blue), except where the blueprinting paper was covered and the light was blocked by the lines of the original drawing. After the paper was washed and dried to preserve those lines, the result was a negative image of white (or whatever color the blueprint paper originally was) against a dark blue background.  White was by far the most used paper and the most common cyanotypes were thus blue with white lines.  At least by 1882 they were being described as “blue prints” but by 1887, they were almost universally called blueprints and in engineering and architecture had become ubiquitous, Herschel’s photochemical process producing copies at a tenth the cost of hand-tracing.

Factory blueprint (quotation drawing produced on diazo machine) of 1955 Mercedes-Benz 300 SLR (W196S Uhlenhaut Coupé).  Two were built, one of which sold in June 2022 for a world record US$142 million at a private auction held at the Mercedes-Benz Museum in Stuttgart.

Refinements and economies of scale meant that during the early twentieth century the quality of blueprints improved and costs further fell but by the 1940s, they began to be supplanted by diazo prints (known also as “whiteprints” or “bluelines”).  Diazo prints were rendered with blue lines on a white background, making them easier to read and they could be produced more quickly on machinery which was simpler and much less expensive than the intricate photochemical devices blueprints demanded.  Accordingly, reprographic companies soon updated their plant, attracted too by the lower running costs, the diazo machinery not requiring the extensive and frequent maintenance demanded by the physically big and intricate photochemical copiers.

1929 Mercedes-Benz SSKL printed in blueprint style.

One tradition of the old ways did however endure.  The diazo machines caught on but “diazo print”, “whiteprint” & “blueline” never did; the drawings, regardless of the process used, the color of the paper or the lines (and many used black rather than blue) continued to be known as “blueprints”.  That linguistic tribute persisted even after diazo printing was phased-out and replaced with the xerographic print process, the standard copy machine technology using toner on bond paper.  Used for some time in commerce, large-size xerography machines became available in the mid-1970s and although originally very expensive, costs rapidly fell and the older printing methods were soon rendered obsolete.  As computer-aided design (CAD) software entered the mainstream during the 1990s, designs increasingly were printed directly from a computer to printer or plotter and despite the paper used being rarely blue, the output continued to be known as the blueprint.

Blueprint of the Chrysler Building, New York City, 1930.

Even now, although often viewed only as multi-colored images on screens (which might be on tablets or phones), such electronic drawings are still usually called blueprints.  Nor have blueprints vanished.  There are many things (buildings, bridges, roads, power-plants, railroads, sewers et al) built before the 1990s which have an expected life measured in decades or even centuries and few of these were designed using digital records.  The original blueprints therefore remain important to those engaged in maintenance or repair and can be critical also in litigation.  Old blueprints can be scanned and converted to digital formats but in many cases, the originals are fragile or physically deteriorated and finer details are sometimes legible only if viewed on the true blueprint.  Centuries from now, magnifying glasses in hand, engineers may still be examining twentieth century blueprints.

Lindsay Lohan, blueprinted.