Sir John Frederick William Herschel, 1st Baronet was an English polymath active as a mathematician, astronomer, chemist, inventor, and experimental photographer who invented the blueprint and did botanical work.

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. 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.