18th November 2021

Cyanotypes – What are they?

Cyanotype is a process I’ve only recently been made aware of. In this week’s blog post on The History of Photography, we discuss cyanotypes. Where they originated and how they are created.

I was very fortunate to have been invited by the Northern Ireland Rural Women’s Network (NIRWN) to recently take part in a fantastic project called extraORDINARY Women in the Linenhall Library, Belfast. This included a wonderful day trip to Belfast along with a number of other women, where we got the opportunity to produce our own cyanotypes. It inspired me to write this blog and share some history behind the process.

The History

Let’s start of with the history of cyanotypes. The origin of the word means blue print. It comes from the Greek word CYAN meaning dark blue. Cyanotype is a photographic process that creates an image with blue tones, instead of the brownish tone of albumen prints or the grey tones of silver gelatin prints.

Back in 1842 Sir John Herschel created with the process of ‘cyanotyping’. This was a cost effective way of reproducing diagrams and written information Hence the term ‘blue print’.

One of his colleagues, Anna Atkins, then pioneered this technique to develop the world’s first photographically illustrated book. She published three volumes of her book Photographs of British Algae: Cyanotype Impressions (1843–53) represent the earliest examples of books illustrated with photogenically produced images.

Anna Atkins Cyanotype
Image credit –

The Cyanotype Process

Similar to the photogram process, a UV light sensitive emulsion is prepared and then applied to a porous surface like paper. Once the paper has dried, you can place a negative or object directly onto it and then expose to natural light. After the desired amount of time has passed, the paper is covered, taken inside to be rinsed and left to stand in water to fix the process.

Why is the finished print blue?

By using a sensitising solution of ferric ammonium citrate and potassium ferricyanide, the end result is a beautiful prussian blue print.

When these iron salts are exposed to natural light, they are reduced to their ferrous state. This produces a blue image when oxidised. The process is accelerated by immersing the paper in running water, which also washes away the unused iron salts.

What do you need to produce a cyanotype print?

To begin with you need two solutions – Potassium Ferricyanide 0.8 oz/23.2 g and Ferric Ammonium Citrate 1.9 oz/54.4g. It’s quite a straightforward process and I can speak from personal experience, having done so recently. Prints can be made on any natural fibre such as paper, wool, wood, cotton or silk. The process is suitable for many types of art papers.

Cyanotype kits are readily available on Amazon and Etsy. The chemicals comes premeasured in lightproof bottles. All you need to do is fill each bottle with water to create the two solution. Then mix them in equal parts to create the cyanotype sensitiser.

Image Credit – Textures Factory

Coat your fabric or paper with the sensitiser and once dry, create your cyanotype print using objects or a film negative to help create an image on the paper. This is then exposed to sunlight, normally around 3-15 minutes, depending on weather conditions.

After exposure, prints are immersed in a tray of cool water and allowed to air dry over about 24 hours. Oxidization occurs resulting in the deep blue coloured print. To speed up the process and produce an instantly oxidize print, submerge the paper in a dilute bath of 3% hydrogen peroxide after washing. Then you can rinse and dry.


To increase contrast and intensify the print, add a few drops of bichromate added to wash water.

My own experience of the Cyanotype process

Bryonie from Quarto Collective guided us through the cyanotype process, making physical images from digital. We got to experience working in the darkroom at Belfast Exposed before carrying our prints outside to develop. It was fascinating watching how the process worked and we were all very eager to see how they turned out.


We were invited to either loan or donate our work to be included in the exhibition and I was very happy to do so. This is a lasting photographic legacy that each of us leaves behind and I for one, was so grateful to be able to do so.

Thank you so much to Northern Ireland Rural Women’s Network, Quarto Collective, Linenhall Library and all the funders for this incredible opportunity. I will remember this day forever

Image Courtesy – AnnMarie O’Neill

I really enjoyed learning about the cyanotype process, which in turn inspired me to write this blog. I loved the simplicity of the finished result. Similar to black and white photography, when you strip away the variety of colours it makes you think. Whilst the end result is not ‘perfect’ photographically, it is still full of impact. For me, this is more of a creative artform. Liberating and inspiring. Accessible to anyone. Allowing you to experiment with the cyanotype process and produce beautiful pieces of art.