Some history, from wikipedia :
Cyanotype is an old monochrome photographic printing process which gives a cyan-blue print.
The English scientist and astronomer Sir John Herschel discovered this procedure in 1842. Though Herschel is perhaps the inventor of the cyanotype process, it was Anna Atkins, a British scientist, who brought the process into the realm of photography. She created a limited series of cyanotype books that documented ferns and other plant life. By using this process, Anna Atkins is regarded as the first woman photographer.
1. Mix two chemicals to create photo sensitive solution of 'sensitizer'.
2. Brush, smear, or soak the sensitizer into cotton-based watercolor paper.
3. Create a negative image on a transperency with a laser/inkjet printer or copy machine.
4. Place the negative over the dried, sensitized paper.
5. Expose to UV light.
6. Wash the image in water to develop.
7. Hang to dry, and enjoy!
Step 1: Chemistry
The cyanotype is perhaps the safest photo printing method. Still, basic safety measures should be observed. Cover your work surface, don't use any utensils that will be used for food, and wear safety gear. In the picture below I'm decked out in safety glasses, a DIY style face mask, and heavy rubber kitchen gloves.
The basic formula (from here):
100 ml water and 25g green ferric ammonium citrate is mixed together.
100 ml water and 10g potassium ferricyanide is mixed in a separate container.
The two solutions are then mixed in equal parts.
What I did:
I could not find the required chemicals in the Netherlands. My cheapest option was to buy from the Photographer's Formulary in the US (even with international shipping).
FAC 100 grams
PF 100 grams
Most tutorials suggests making 100ml of each solution. I didn't want to store these liquids so I made a much smaller batch. I chose to make 5ml of each solution, to be mixed for 10ml total sensitizer.
I do not have a scale, so I estimated the volume of each chemical I needed based on the overall size of the bottles (100g). I mixed a very rough 0.5g PF and 1.2g FAC each to 5ml de-mineralized water (used for clothing irons, car batteries, etc. Sold in bottles in the Netherlands for ~50 cents). These were mixed individually and then combined, as per the instructions above.