A blue printed image prepared by a nonsilver process that was popular for photographs at the end of the 19th century. More recently, cyanotypes, or blueprints, were primarily used to copy architectural drawings. The cyanotype method was suggested in 1842 by British astronomer Sir John Herschel but not widely used until the 1880s after Henri Pellet developed a direct positive blueprint process (1877). In this process, cyanotype paper is coated with a ferric and an organic acid in a binder (Dextrin, Gum, or Gelatin); after exposure to light the image is developed with potassium ferricyanide which reacts to form Prussian blue. The blue image on white paper is fixed by washing the remaining salts away in an aqueous solution.
Synonyms and Related Terms
blueprint; blue print; Prussian-blue process; Pellet process; pelletones
- Highly sensitive to alkalis.
- Should not contact buffered paper.
Resources and Citations
- Encyclopedia Britannica, http://www.britannica.com Comment: "Blueprint." Accessed 29 Apr. 2004 .
- Alternative Photography: Cyanotype History
- The Dictionary of Art, Grove's Dictionaries Inc., New York, 1996 Comment: "Photography"
- Luis Nadeau, Encyclopedia of Printing, Photographic, and Photomechanical Processes, Atelier, New Brunswick, 1997
- Caring for your Collections, Arthur W Schulz (ed.), Harry N. Abrams, Inc. , New York, 1992
- AMOL reCollections Glossary - http://amol.org.au/recollections/7/c/htm
- Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997
- The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998