CYANOTYPE

The cyanotype process was one of the first non-silver technologies used to create photographic images. Originated in the 1840’s, it was not utilised in mainstream photography and was adopted as a copying technique, becoming known by the term “blueprint”, with its blue background reproductions of large architectural and mechanical drawings.

Two solutions are prepared for the two-part sensitising process. Material sensitised with the solution is then printed by ultraviolet light.

Cyanotype is a negative process – areas where light does not hit sensitised material will remain white. Contact print by placing negative on your sensitised material. Expose to strong sunlight or UV light until the high values are a little too dark and the shadows have begun to reverse. You can use test strips to test light to determine best exposure time.

Prints can be made from large format negatives and lithography film, digital negative or everyday objects can be used to make photograms.

In a cyanotype, a blue is usually the desired colour; however, there are a variety of effects that can be achieved. These fall into three categories: reducing, intensifying, and toning.

Toning is the process used to change the colour of the iron in the print cyanotype. The colour change varies with the reagent used. 

Related article-  https://www.sciencecompany.com/The-Cyanotype-Process.aspx

Chemicals needed for the process-

25gm ferric ammonium citrate

10 gm potassium ferricyanide

200 ml distilled water each for part A and B

Part A

Take 100ml distilled water

10gm potassium ferricyanide ( mix well)

Part B

Take 100ml distilled water

25gm ferric ammonium citrate

Then mix Part A into Part B slowly and keep stirring it for sometime. ( Always add part A into B)