How to Make a Cyanotype – Practical Steps and Tips
So you’re interested in making some cyanotypes, but you’re not sure where to start. Well, I can give you some help with that. Let’s start at the beginning, shall we?
In essence, what you will need to do is get the cyanotype chemicals onto your paper (or whatever you’re cyanotyping), position whatever you’re going to make an image of, expose it using UV light, and then develop/wash and dry it. Voila, cyanotype! Ok, it’s not quite that simple so let’s go through things in a little more detail.
First things first you need the correct chemicals. You can buy these in the form of a kit, precoated onto paper or as raw chemicals and mix them up yourself. If you go for the precoated paper option then you can skip this bit – you’re paper is already prepared for you. If you’ve bought a kit then the kit should have instructions with it. Your chemicals are most likely already mixed, you just need to put them together and then paint them onto your paper.
However, if you’d like to make up the chemistry yourself here’s how. You will need :
- Ferric ammonium citrate (often referred to as green)
- Potassium Ferricyanide
- Water (Distilled if you have it)
- Measuring Scales (for the chemicals)
- Measuring Cylinder or Jug (for the water_
- Containers to put them in
25g of Ferric Ammonium Citrate in 100ml of water 10g of Potassium Ferricyanide in 100 ml of water.
Use your measuring scales to measure out 25g of Ferric Ammonium Citrate in a clean container. Some people say that this should be a glass container but honestly, a clean plastic one will be fine. I save old food tubs such as yoghurt pots, make sure they’re squeaky clean and then use them. Then use your measuring cylinder or jug to measure out 100ml of water. This is often quoted as needing to be distilled water which works great but you should also be able to get results with ‘regular’ water. Mix the two and put them to one side. This is now your solution A.
Repeat but with 10g of Potassium Ferricyanide and 100 ml of water. This is now your solution B.
You can do all of this in daylight as these solutions are not light-sensitive. They only become sensitive to light once you mix the two solutions together. However, the next step is to mix them together in equal parts to make the cyanotype solution, at this point it will immediately become sensitive to UV light. UV light is emitted by the sun so doing this in sunlight isn’t a good idea as the mixture will immediately begin to expose. You can do it under artificial light as light bulbs usually only emit a tiny amount of UV. If in doubt mix them at night and put them into a dark bottle if possible.
Coating the Paper
Once mixed you can start coating your paper. You will need to lay your paper out but before you do, consider the surface it’s on. Any drops of the cyanotype formula are likely to discolour the surface they land on – so it’s a good idea to cover that beautiful kitchen table with a plastic sheet to avoid any problems.
You can use a brush or sponge to get the solution onto the paper and then place them somewhere away from UV light and leave the paper to dry. If you want to you can put a second coat once the first is dry. You should wear gloves for this to prevent getting any chemicals on your hands.
Now comes the fun bit.
Composing and Exposing your image
Lay your paper out and place whatever you’ve chosen to make your image on top. Check you’re happy with the composition and then expose it to UV. You can use a UV lamp or beautiful sunshine.
A common way of keeping everything in place during the exposure is to use a sheet of glass or a photo frame. You don’t however need to do that, it’s just to help prevent anything from moving about.
How long to leave your image to expose depends upon the amount of UV light used. What you’re looking for is a change in the colour of the cyanotype chemicals which you can still see. They should go from a sort of murky yellow to a darker yellowy-bluey green. At this point, your image is ready to be developed and washed.
Prepare some water in a tray or shallow dish large enough to fit your paper. If you don’t have one then you can rinse under a tap. Remove everything from on top of the paper and place it into the water. The chemicals which were covered and not exposed to the UV will slowly wash off in the water. Some gentle swishing will help with that. Use gloves and / or tongs to keep the chemicals off your hands for safety.
Once fully washed (no more chemicals washing off) hang your masterpiece up to dry (clotheslines are great for this). Once dry you can get rid of any warping of the paper by placing it under a pile of books to flatten it. The colour will already be blue by this point but will darken over 24 – 48hours to the full iconic Prussian blue colour this process is known for.
The chemicals used can cause irritation so I’d recommend wearing gloves and washing your hands straight away if you get any on them. You should also consider other forms of protection such as glasses, masks etc. Check any safety instructions which come with the kit you’re using or the chemicals purchased and make an informed decision.
You should also consider protective clothing to protect your clothes or wear old clothing.
About the Process
These instructions are for the classic cyanotype process developed by Sir John Herschel in 1842. There is a ‘new’ cyanotype process which was developed by Dr Mike Ware however I prefer the original formula.