Is it raining? Head to the kitchen

And transform the colours of your cyanotypes!



It still is summertime, officially. However, the sun is playing hide and seek… What to to with cyanotypes on a rainy day? I suggest you go to the kitchen.


In my previous blog post I shared with you the steps to make cyanotypes as well as tips and tricks I learned along the way. I also revealed that some people around me do not mike cyanotypes because they are always blue…




In this blog post and as promised, I am showing you how to change the colours of cyanotypes by bleaching an toning them. You will see that an original cyanotype can be yellow, brown and even of a very beautiful black.


From Prussian blue to deep black : toning

A solution containing tannin will tone a cyanotype. Depending of the tannin used, the black can be cool or warm.

  • With coffee, one obtains a cool black

  • With tea, a dark warm black. Green tea gives a lovely pink hue to the paper and stains less the paper than bkack tea.

I use a least eight teaspoons of soluble coffee for one liter of water or at least six tea bags. I leave it to rest to cool (at body temperature) and then soak the cyanotype for 10 to 20 minutes according to the desired colour. I rince the cyanotype thoroughly and let it dry.


I prefer using green tea and love the lovely smell in the kitchen during the process ! Anything that contains tannin can be used. Some people use strong red wine to obtain a dark aubergine colour.

From Prussian blue to pale yellow: bleaching

It is preferable to use a cyanotype having its final colour, at least 24 hours after having been done.



I dissolve one teaspoon of caustic soda (we find that in supermarkets in France) in one liter of water.


This is dangerous. It is supra important to read and respect the procedure and safety instructions on the paquet. You must wear gloves and be careful with your eyes and respiratory tract.







I soak the cyanotype in this solution until it becomes yellow and rinse several times and leave it to dry. This is fairly quick (3 to 5 minutes).










From pale yellow to brown: toning the beached cyanotype

By toning a bleached cyanotype, one obtains a light to dark brown according to the soaking time. Play and observe!


And after that ?

Other forms of play are allowed with cyanotypes: wet cyanotypes, adding salt and other ingredients… I may share some of my experiment in a further blog post. In the meantime, I will be super happy to admire your creations if you care to share them with me!