Ben Rider is a well-known print technician at Print Club London. He is a London-based illustrator as well as a graphic designer who is well-versed in various print techniques. One of those print techniques happens to be Cyanotype. This is a printing process that is regularly used by engineers and architects to create blueprints. Cyanotype is a printing process that uses photographs to produce a cyan-blue print. It is a simple and relatively low-cost process that can be used to produce many copies of drawings, which are referred to as blueprints. The process utilizes the chemicals ammonium iron(III) citrate and potassium ferricyanide. The chemicals are mixed in equal volumes and then applied to a receptive surface, like paper or cloth, and dried in a dark place. Any surface capable of soaking up the iron solution can be used. To make a positive image, the surface has to be exposed to a source of ultraviolet light through a contact negative. The UV light reduces the iron(III) to iron(II), which then reacts with ferricyanide to create an insoluble, blue dye known as Prussian blue. Exposing with UV light causes the paper to turn a steel-grey-blue color. The amount of color change depends of the amount of UV light used. After exposing, developing the picture involves rinsing the yellow unreacted iron solution off with water. The water-soluble iron(III) salts are washed away leaving the non-water-soluble Prussian blue in the paper. This creates the typical blue color.
Here is an example of Ben Rider’s process and final Cyanotype.
Art by Michelle 