n.A photographic process that uses Prussian blue for the image to produce a positive print from a negative.A print made by the process.


Cyanotype is identical to the blueprint process, but the former is typically used to describe continuous-tone photographic prints, while the latter is used to describe reproductions of line drawings. The Pellet or blueline process produces a positive image from a positive image. Typically on paper but sometimes on cloth or another support. The process was invented by Sir John Herschel in 1840 and remains in use today.