Cyanotype

The blue of light

Cyanotype is one of the oldest photographic techniques: it dates from 1842. Two iron salts, paper and sunlight. That’s it. The result is a print in a deep blue — Prussian blue — that doesn’t fade, doesn’t yellow with time, and requires neither a darkroom nor hazardous chemicals.

But its simplicity doesn’t make it simple. Cyanotype responds differently to each paper, each light, each emulsion. Learning to read it is learning to respect imprecision as part of the process.

In this workshop we prepare the solution, coat the paper, expose it with sunlight or ultraviolet light and develop with cold water. We work with negatives printed on transparency film, but also with photograms — objects placed directly on the paper — to understand the process without intermediaries.

Key contents

• Origins and context of cyanotype within alternative processes
• Preparing the ammonium ferric citrate and potassium ferricyanide solution
• Coating the paper: materials, thickness and drying
• Exposure: light, time and distance variables
• Water development: washing, oxidation and spontaneous toning
• Variations: printing on fabric, wood and other supports
• Photograms: working without camera or negative

What’s included

• Chemicals: ammonium ferric citrate and potassium ferricyanide
• Papers in various weights (watercolour, kraft, smooth)
• Sample acetate negatives
• Objects for photograms
• Use of the lab and solar/UV exposure space

What to bring

• Your own photos converted to negative on acetate (optional; if you don’t have any, we generate them in the session)
• Personal objects for photograms if you want to use them (leaves, fabric, transparencies…)

Not included

• Printing of additional acetate negatives (+materials, enquire)
• Alternative supports such as fabric or wood (available as an extra option)