![cover image](https://wikiwandv2-19431.kxcdn.com/_next/image?url=https://upload.wikimedia.org/wikipedia/commons/thumb/a/a4/AcotacionTecnico.svg/640px-AcotacionTecnico.svg.png&w=640&q=50)
Blueprint
Document reproduction by contact printing on light-sensitive sheets / From Wikipedia, the free encyclopedia
A blueprint is a reproduction of a technical drawing or engineering drawing using a contact print process on light-sensitive sheets introduced by Sir John Herschel in 1842.[1] The process allowed rapid and accurate production of an unlimited number of copies. It was widely used for over a century for the reproduction of specification drawings used in construction and industry. Blueprints were characterized by white lines on a blue background, a negative of the original. Color or shades of grey could not be reproduced.
The process is obsolete, largely displaced by the diazo whiteprint process, and later by large-format xerographic photocopiers. It has almost entirely been superseded by digital computer-aided construction drawings.
The term blueprint continues to be used informally to refer to any floor plan[2] (and by analogy, any type of plan).[3][4] Practising engineers, architects, and drafters often call them "drawings", "prints", or "plans".[5]