Cyanotype printing

I read about the cyanotype process on the Alternative Photography website.

I bought my chemicals (Ferric Ammonium Citrate & Potassium Cyanide) from www.Silverprint.co.uk, which I mixed separately to the recipe specified on Alternative Photography (25g FAC to 100ml water, 10g PC to 100ml water) in brown glass bottles which I was able to purchase at the pharmacy (light safe).

As the chemicals (when mixed) are light sensitive, it is essential to work in a dark room. I did this by blacking out the window of the spare room with thick black plastic. The only 'safe' light to work in is a tungsten bulb (this is a normal energy saving bulb).

I ripped a sheet of A1 cartridge paper into pieces just larger than my medium format negatives and coated these (with an equal measure from each bottle, mixed) using a foam brush for speed and to ensure a solid finish without brush strokes or gaps. I was able to paint these under the tungsten light and left them to dry in complete darkness.

 Select items to make a 'resist' print, choose negatives or transparancies and lay these out. Resist items tend not to need pressing under a sheet of glass, where as I would consider it a crucial step for negatives as they have a tendency to curl (leaving you with a blurry finish).

Resist cyanotype printing

Paper coated and dried in the dark, shells arranged.

After two hours, indirect sunlight.

Once the print achieves a steel grey type tone, it is ready to be rinsed in cold tap water.

Negative/Transparancy cyanotype printing

 These negatives have a good range of tone, which I hoped would be reflected in the finished print.

12pm - 11am exposure

25 negatives under glass

I rinse the prints 5 at a time in 8 litres of cold tap water. It is essential to change the water this frequently as any under-exposed chemical rinses away, so as a consequence the water stops 'washing'.

Cyanotypes drying flat on the table, afte rinsing

The exposed prints look very dark blue/grey, most of this washes away to reveal a bright cyan print. Negatives with very dark overall tone will need to be exposed for long periods of time if the sunlight isn't strong and direct. Any under-exposed print will simply wash away, leaving a frame on the paper. This is due to the negative being harder to penetrate than plain paper.

This print has exposed perfectly and the tonal range is superb.

This print is under-exposed, yet the image is still on the paper. This negative had an overall darker tonal range.

This print has exposed well and is crisp.

Completely under-exposed, image washed away.

Exposure time varies from day to day, time of year, time of day, situation of exposure. I experimented with exposing half a print, almost a test strip.

The half with the image remaining was exposed for half an hour, in direct sunlight. The covering paper was then removed, leaving the whole image to develop for another half an hour. In the second and final half an hour, the sun went in and a significant difference can be noticed. This half of the image has washed away completely, where as the remaining image is not too far off developed. This clearly indicates the importance of experimenting with exposure times at different times of day.

Toning cyanotypes with tea and coffee

I made the coffee solution by mixing one heaping tablespoon of cheap instant coffee with 500ml of boiling water, stirred and left to cool. Coffee gives COLD tones.
I made the tea solution with four cheap teabags with 500ml of boiling water, steeped for five minutes, teabags squeezed and removed, left to cool. Tea gives WARM tones.

I left the prints to soak, one at a time, face down in the tea/coffee. These prints were a couple of weeks old, and the emulsion was set. New prints (same day) will be too unstable to tone straight away.

Some sources suggest bleaching the prints first, however I find the prints tone well enough without this process.

2 hours, Tea.

5 hours, Tea.

5 hours, Coffee.

2 hours, Coffee.