Experiments with Cyanotypes

Background

Cyanotype is an image-making process that uses two chemicals, ammonium ferric citrate and potassium ferricyanide. When these two compounds are mixed together and applied to a surface (such as paper) the surface becomes photosensitive and can be used for contact printing. One of the great things about the cyanotype process is that images can be created in sunlight and developed with plain water. Cyanotypes were also the original technique for producing blueprints.

This page is intended to be a living document cataloging various approaches I have personally tried in respect to the cyanotype process.

Experiments

1. Development

• When cyanotypes are developed in plain water the print will darken dramatically as it dries. You can get a sneak peek at the final color by soaking your print in a roughly 10:1 mixure of water and hydrogen peroxide after the initial wash. You should see rich blues emerge instantly.

• Rinsing your print in a potassium ferricyanide and water bath has been said to increase contrast and result in darker blues. I haven’t found much success in this, however.

2. Toning

• Toning in general can be more successful if you first ‘bleach’ your print in a borax or soda ash bath. Further testing is needed to determine appropriate concentrations and timings.

• Soaking your print in coffee after the initial wash can darken your blues to dark navy or black.

• Green tea can tone your print to a dark magenta.