Cyanotype.

How to recognize it.

1. Blue-and-white contrast
2. Silhouetted forms
3. Soft contact edges

Context & origins.

The cyanotype is a photographic process devised by Sir John Herschel in 1841 that produces a continuous-tone image in Prussian blue. It relies on a sensitising solution of ferric ammonium citrate and potassium ferricyanide, whose iron salts are reduced when exposed to natural or artificial ultraviolet light and then yield a high-contrast blue image on oxidation. The process was long used to copy engineering and architectural drawings before photocopiers became common, and photographers also used it for botanical records, still lifes and proof prints from negatives.

Historical context draws on the supplied research. Approximate periods are reference ranges, not fixed boundaries. See the source notes below.

In practice.

Use a small number of strong silhouettes and leave the tonal field intact.

What to watch for

A blue filter on a photograph does not reproduce the contact-print process.

These are editorial design observations, not rules for classifying every work.

Visual characteristics.

grid discipline

not applicable

palette logic

monochrome

contrast

medium

texture

subtle

hierarchy

not applicable

ornament level

not applicable

Sources & further reading.

1. Supplied research: Graphic Design Movements 1850–2000 ↗cyanotype.mdConsulted 2026-09-24