A cyanotype is one of the earliest photographic printing processes, producing distinctive Prussian blue images through a light-sensitive chemical reaction. It is a contact-print process that uses sunlight or UV light to create images on paper, fabric, wood, and other surfaces. Cyanotypes sit at the intersection of photography, printmaking, and painting, which is part of what makes them so enduring and magical.

1842 — The Beginning

The cyanotype process was invented in 1842 by Sir John Herschel, an English astronomer, chemist, and scientist. Herschel developed it while experimenting with light-sensitive iron salts.

Unlike silver-based photography of the era, cyanotypes used iron compounds, making the process simpler and more affordable.

1843 — The First Photographic Book

Anna Atkins became the first person to publish a book illustrated entirely with photographs.

Her groundbreaking work, Photographs of British Algae: Cyanotype Impressions, used cyanotypes to document seaweed specimens.

Because of this, Anna Atkins is often considered:

One of the first female photographers

The first person to create a photographic book

A pioneer of botanical photography

Blueprint Era

By the late 1800s, cyanotypes became widely used by architects and engineers.

The process created inexpensive copies of technical drawings called Blueprints.

The word “blueprint” literally comes from the cyanotype process.

Blueprints remained standard until the late 20th century.

Modern Revival

Today, cyanotypes have experienced a major resurgence among the following:

Fine artists

Mixed-media creators

Printmakers

Textile artists

Nature artists

Alternative photography enthusiasts

Artists now create cyanotypes on:

Watercolor paper

Fabric

Wood

Glass

Ceramics

Handmade paper

Found objects

The process uses two chemicals:

-Ferric Ammonium Citrate

-Potassium Ferricyanide

These are mixed and brushed onto a surface.

Steps:

Coat paper or material with the solution.

Let dry in darkness.

Place an object or a negative on the surface.

Expose to UV light or sunlight.

Rinse with water.

Image develops into rich blues as it oxidizes.

Areas exposed to light turn blue while blocked areas remain light.

• Cyan comes from the Greek word kyanos, meaning “dark blue.”

• Fresh cyanotypes often darken over the first 24–48 hours as oxidation continues.

• Tea, coffee, wine, tannins, and natural dyes can tone cyanotypes into brown, sepia, purple, black, or warm neutral colors.

• Plants are one of the most common subjects because leaves and flowers create striking silhouettes.

• Cyanotypes can continue developing slightly after washing.

• Exposure times can range from a few minutes to over an hour, depending on UV strength.

• Rainy or cloudy days often create softer, more subtle prints.

Color: Deep Prussian blue

Process Type: Alternative photographic printing process

Invented: 1842

Inventor: Sir John Herschel

Light Source: UV light or sunlight

Difficulty: Beginner-friendly

Common Subjects: Botanicals, negatives, lace, feathers, objects, silhouettes, textures