Cyanotype is a method of print making that has many advantages to a modern printer. It's easy to get started, cheap, has very fine actuance, and can be toned into many colors beyond its natural blue.
The cyanotype process is most sensitive to UV and fairly slow, makding it unsuitable to use with traditional enlargers. Given that our best method for making larger prints is to make contact prints. In most of the course of photographic history this meant creating huge negatives in camera, but with the advent of high quality inkjet printers we're able to print a high resolution digital transparency and use that instead. As print makers this gives us all of the powers of digital processing; digital editing, collage, adjustments; At the cost of having to sit in front of a computer.
Once you have a transparency, making a cyanotype isn't complicated. First the paper is coated; starting with a suitable paper, the sensitizzer is spread onto the paper and then the paper is dried. Then the print is exposed; the transparency is squeezed against the sensitized paper and exposed to bright UV light. Finally the print is developed by washing it in a bath of acidified water.
Materials
- Printing Frame - A printing frame is a tool that holds the negative to the sensitized paper. On the cheapest end you can get by with a heavy piece of glass, on the most expensive are fancy hand made wood frames.
- 365nm UV Light - Cyanotype is a UV process, traditionally you might use the sun, but it's inconsistent (especially here in the northwest winters). A 365nm UV light goes a long way to making this process simpler.
- Paper - There are endless variants of fine arts papers to expirement with, I predominantly work with Arches Platine 145gsm, but there are a ton great options. Take a look at Christina Anderson's MASSIVE Paper Chart for ideas on what works best.
- Sensitizer - There are two formulations of cyanotype in wide use today: Classic two part cyanotype, and Mike Ware's "new" one part. Which you use is up to you, I use the new variant, I'll include ingredients for both below.
- Brush - There are a handful of ways to coat paper but a brush is probably the most common. I like to use a japenese hake brush but lots of folks like foam brushes. Importantly don't choose a brush with metal ferules as they can react with the sensitizer.
- Trays - Three low trays that fit your print.
- Clothes Pins - Plastic, for hanging your prints.
- Citric Acid - Used in the first wash, helps prevent washout.
- Scale - Accurate to 0.01g, after trying a number, I really like the american weigh scales.
- Brown Glass Bottles 100mm - I got mine at the UW surplus store
- 100mm Graduated Cylinder
- Tween 20 - A common surfectant, it can help with sensitizer penitration
Making Sensitizer