chemia: Cyanotype

Evidence: 100 • authority: 72

The cyanotype (from Ancient Greek: κυάνεος, kyáneos 'dark blue' and τύπος, týpos 'mark, impression, type') is a slow-reacting, photographic printing formulation sensitive to a limited near-ultraviolet and blue light spectrum, the range of 300 nm to 400 nm, known as UVA radiation. It produces a monochrome, blue-coloured print on a range of supports, and is often used for art and reprography in the form of blueprints. For any purpose, the process usually uses two chemicals – ferric ammonium citrate or ferric ammonium oxalate, and potassium ferricyanide, and only water to develop and fix. Announced in 1842, it is still in use.

Evidence: 37 • authority: 80

Photography. Processing chemicals. Specifications for potassium ferricyanide

Evidence: 37 • authority: 80

Photography. Processing chemicals. Specifications for potassium ferricyanide

Evidence: 37 • authority: 72

A heliographic copier or heliographic duplicator is an apparatus used in the world of reprography for making contact prints on paper from original drawings made with that purpose on tracing paper, parchment paper or any other transparent or translucent material using different procedures. In general terms some type of heliographic copier is used for making: Hectographic prints, Ferrogallic prints, Gel-lithographs or Silver halide prints. All of them, until a certain size, can be achieved using a contact printer with an appropriate lamp (ultraviolet, etc...) but for big engineering and architectural plans, the heliographic copiers used with the cyanotype and the diazotype technologies, are o…