Care of Cyanotypes

English astronomer and scientist Sir John Herschel discovered the cyanotype process in 1842. In its early days, the process facilitated the reproduction of  notes and diagrams, hence the term “blueprint.” Amateur botanists adopted the process for the purposes of plant illustration: they placed the specimens onto coated paper and allowed the action of light to create a silhouette effect. English botanical artist, collector and photographer Anna Atkins published the first book of photographic images using her cyanotypes (British Algae: Cyanotype Impressions).

In the case of my prints, a negative is placed in contact with the sensitized paper, and exposed by a UV light source (either the sun, or an artificial UV light source).   The extent of color change depends on the amount of UV light that passes through the negative. 

Alkaline environments can cause fading of cyanotypes.  The “buffered, acid free” mat boards should be avoided when matting and framing a cyanotype.  Look for un-buffered museum rag board for matting cyanotypes, and the same for backing board when framing them. 

Redimat carries un-buffered mat board in a variety of sizes, and also un-buffered mat board blanks for backing boards when framing.  

There is a link in this article to their un-buffered mat board selections: https://www.redimat.com/articles/buffered-v-unbuffered.html

One interesting characteristic of the cyanotype is its regenerative behavior:  prints that have faded due to prolonged exposure to light can often be significantly restored to their original tone by simply temporarily storing them in a dark environment.  Atkins’ cyanotypes have been hanging on a wall for 150 years, and show no sign of fading. With proper care, they should live a long time. 

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The article above is a collaboration between Christine Buckley and myself.