This post will briefly cover the history & science of cyanotypes, before comparing the three main options on chemicals. We’ll then look at how to actually make an exposure before looking at some tips on timing, photograms and contact prints.
History & Science
A Mini History of Cyanotype
The cyanotype process produces a beautiful, Prussian-blue coloured print. The process was developed in 1842 by Sir John Herschel, an English astronomer, as an easy way to make copies of diagrams. For much of the 20th century cyanotypes continued to be used as a quick way to produce copies of technical drawings for engineering and architecture. These were called blueprints, and the term is often still used today.
The cyanotype process was quickly picked up by artists and was very popular during the Victorian era. Anna Atkins, sometimes called the first female photographer, began using cyanotypes to create images of her botanical collections, and published a book of cyanotype images in 1843. This is thought to be the first ever book illustrated with photographic images.
The Science of Cyanotype
A very basic idea of how the science works.
The Chemical Bit
Cyanotypes use a mix of two chemicals; Ferric Ammonium Citrate and Potassium Ferricyanide. The mixture of chemicals produces a light sensitive iron complex. When exposed to ultraviolet light the iron becomes unstable and combines with ferricyanide to produce a more stable iron molecule which produces the classic cyanotype blue. The unexposed chemicals don’t change, and rinse out easily in water. You’ll see them coming out as the yellow/ green colour in the water as you rinse.
Basically This is What Happens
When you expose your paper, the parts that sunlight reaches will remain blue, the parts where it can’t reach will be white when the paper is rinsed. You can create various blue tones by varying these light levels during exposure, by using a negative or by moving items around if you are making a photogram.
Options on Chemicals
There are three main choices of where to start with creating your cyanotype. I’ve listed them from lazy photographer to obsessive.
1 The easiest way to create a cyanotype is to buy some pre-coated paper, like Sunprint paper. This option is safe, quick and easy, so brilliant for beginners & children. There are no messy chemicals to handle and mix, and the unexposed coated paper lasts well as long as you store it in its light-proof packaging. However, the paper is thin, it’s more expensive than other options, and there are not many suppliers so it can be difficult to source.
|Easy to Use||Not much choice of supplier|
|Stores well||No paper choices|
2 Next in terms of ease is to use a Cyanotype kit. These tend to have two bottles which are solutions of Ferric Ammonium Citrate and Potassium Ferricyanide. You mix the solutions together in equal quantities and then use the mixture to coat paper which may be provided in the kit, or paper of your choice.
The problem with pre-mixed liquids is that you don’t know how long they’ve been stored for before you get them, and although individual solutions will last a reasonable length of time, the longer the storage the more likely you are to experience quality issues. These kits also tend to give out plastic bottles & utensils.
However, if you know you want to create a reasonable amount of cyanotype prints or you have a specific surface to coat, this can be a good option.
|Mix as needed||Can be expensive|
|Coat any paper or fabric*||You don’t know how old solution is when you get it|
|Fresh solution lasts six months||Can create waste|
3 The most complicated option is to use powdered chemicals. These powders need to be weighed, water added to make the two solutions, then these solutions are mixed together and used to coat paper or fabric. This can be a bit messy and time consuming, but is probably the cheapest way to make cyanotypes if you’re planning on producing a lot.
You’ll need to use paper with a high cotton content. When choosing paper, think about the type of result you want to achieve. For very crisp results chose hot-pressed watercolour papers, for more texture you can try cold-pressed papers or Khadi paper.
Fabriano (Acquarello) papers are a popular choice, but I’ve used paper by Daler Rowney, Khadi, and even packing paper I found in my Amazon delivery and all have worked perfectly well. Whatever paper you choose, remember it will have to stand up to being rinsed thoroughly.
|Very long lasting & easy to store||Messy|
|Can create a lot of solution||Dangerous to breath in|
|Cheap||Sometimes difficult to obtain|
Creating Your Cyanotype
So you have your paper, it’s a nice sunny day and you’re ready to go. Now what?
Exposing Your Paper
Arrange your artwork on your cyanotype paper indoors or outside in a shady spot. Try to work reasonably quickly if you are outside – even in the shade the paper is being exposed to UV light. When you’re ready, place it in direct sunlight to expose the paper.
When you think the exposure is finished, rinse the paper thoroughly in water. The water will turn a yellow colour where the chemicals are being rinsed out of the unexposed parts of the paper. Rinse until the water is clear.
Leave your paper to dry. You’ll notice that the image will continue to change as it dries. Sometimes it’s a good idea to take photographs of the various stages as the image dries as interesting colours can come and go.
Want a bit more information than that? Let’s look at exposure, and a few different ideas for how to make an image.
Because the levels of UV light vary depending on latitude, time of year and weather, it’s very difficult to give advice about timing or exposure. Development time can change from minute to minute depending on the conditions in the UK. The exposed paper tends to turn a dark blue/charcoal grey when it’s being exposed, so when you see this very dark blue/ charcoal colour, the image will have been exposed for long enough to create a cyanotype.
However, if you want to be as precise as possible with your exposure, you can create a test strip.
Remove a strip of your coated paper, and create marks along it, dividing it into about 10 even sized bits; they don’t have to be exact, this is just a test. I put a piece of grass on my test strip so I can check the whites, and then cover it all with a heavy piece of paper or card that will block the light. The idea is to gradually reveal each piece of the strip. So if you reveal and expose the first strip for 2 minutes, then reveal and expose the second piece for 2 minutes, then move the paper down further and expose the third strip for 2 minutes, the first will have been exposed for 6 minutes, the second for 4 the third for 2, etc. Obviously, as you go along you’ll get a strip where from the bottom, each section will have twice the exposure of the one before it.
How long each section should be exposed for depends on how strong UV light is where you are. In the UK on a medium/ high UV day, I’d go for about 2 minutes per section for 10 sections.
When you’re done, rinse it under cold running water and for best results allow it to dry. You now have a strip showing you what your exposure will look like for each time period.
Most cyanotype fans begin with photograms as they’re fun and easy to create, but can give stunning results.
To create a photogram, you can use any objects with an interesting shape. Place it on your cyanotype paper and expose the paper on a bright, sunny day.
This is the technique Anna Atkins would have used to create her images. It’s the easiest way to make a cyanotype and a lot of fun. Plants are traditional, but experiment with various opaque and semi-transparent items, or even fabrics. You could try a favourite toy, a feather, your hand, a spring, or keys. Sir John Herschel used lace to make cyanotypes. Try arranging items in patterns, and if you’re using lots of objects remember that you don’t have to leave every object on for the whole time. You could remove some objects after a little while to create various blue tones or patterns.
For best results arrange your objects on your paper indoors, and if your items are light then cover them with a clear acrylic sheet or a piece of glass to stop them moving around and to keep them lying flat. If objects aren’t lying flat then the edges will be blurry.
You can’t always tell exactly what will happen with a photogram, but think about shadow shapes and how much light gets through your objects to help you figure out what your image might look like before you start.
If you made a test strip you can use it to see how long you might expose to get different shades of blue. This image was created by removing some of the foliage after a few minutes. Although it’s not particularly successful, it illustrates the way blue tones can be created.
You need to produce a negative the same size as your required print for this technique. You can use one of your own digital photographs, or download a test negative from Epic here. Print it onto transparent material, like inkjet transparency film, to create a negative.
If you use your own photograph then as well as a printer you’ll need access to some software so you can create your negative. You might be able to do this on your phone, but there are a few steps you’ll need to take to make a negative:
- Make your image black & white.
- Adjust the contrast of your image. An image works well if it has some black areas and some white areas. If the image is very grey without much black or white then it might not make a good cyanotype. Adding more contrast can help with this.
- Invert your image. This step makes all the dark bits light, and the light bits dark – it makes it a negative.
- Print the image in black ink onto transparent material. You can get specialist materials, but for most purposes inkjet transparency film works well.
It helps if you have a stiff base of some sort to make a contact print. Even thick cardboard will do, but it needs to be slightly larger than the cyanotype paper you’re going to use.
Put the cyanotype paper onto the base, and put the negative onto the cyanotype paper, and a clear acrylic sheet or glass on top of all that. Fix it down, but remember the fixings will show in the final image if they pass the edges of the cyanotype paper or create a shadow over it. If you’re going for a really good print, creating an exposure test strip with the negative in place will help you get the best results.