Back in the early days of scientific photographic progression people where constantly experimenting in ways of capturing a permanent image in chemicals. One of the methods to emerge from this study was the Cyanotype process.
There are two main chemicals required for making a Cyanotype image, Ammonium Ferric Citrate and Potassium Ferricyanide.
For our class we mixed 10g of Ammonium Ferric Citrate with 50ml of water that was measured to 20°c and then 4g Potassium Ferricyanide with the same water mix. Once we had the two chemical mixtures we stored them in marked brown glass bottles.
If we mix these two solutions together then they will become sensitive to light so at this point we switched to a red safe light in order to avoid unnecessary exposure. We mixed the liquids in a plastic tray and then using a soft brush we carefully painted the surface of a piece of white paper with a thin coating. The liquid is not hazardous but before beginning this procedure we put on protective gloves as it can stain quite badly and leave the hands yellow and marked. Once our paper surface was covered we dried it using a hair dryer and placed it into a light tight box.
Creating an image is a camera less process similar to making photograms and I chose to use a medium format negative as my object. Pretty much anything will work and one popular idea is to invert a digital image in Photoshop and print it onto a acetate. This makes a large negative ready to be transferred onto almost any surface type.
Once you are ready you can expose the paper in a various ways. Often it is a simple case of placing object and paper in direct sunlight but this works better on bright sunny days and it was dull and overcast for us. We used a large flatbed UV machine to recreate the sun and expose our paper. By putting the two together and shining light directly onto them for several minutes I was able to transfer my negative onto the paper. Once the exposure was complete it required me to wash away the remaining light-sensitive chemicals by carefully rinsing the paper under a cold tap. As the water ran over the paper the image miraculously appeared and all that was left was for it to be hung up to dry.
What is fascinating about this method is the ability to make almost any surface light-sensitive. This opens up a world of possibilities with the ability to combine any number of images and objects to create a narrative. One of our assignments is to make images around the subject of Human Presence using an alternative process. I think this would be a great way to explore this further and I would like to try using a range of materials.