How to make a cyanotype print

A cyanotype is a sun print: paper coated with a light-sensitive solution, covered with an object or a negative, and left in sunlight until the exposed parts turn Prussian blue. These are the steps, quoted from a maker of the chemistry and from a museum, with a link to each source.

What you need

The sensitizer. The Getty Museum describes what a cyanotype is made with:

“A cyanotype—a type of photogram—is made by laying the subject material directly on top of a regular piece of writing paper (British Whatman Turkey Mill paper in Atkins’s case) that has been coated with iron salts of ferric ammonium citrate and potassium ferricyanide.” [Getty Museum, Anna Atkins, British Algae]

Something to print on. Jacquard says what takes the sensitizer:

“Yes, any natural surface can be treated with the cyanotype sensitizer, including silk, cotton, wool, hemp, linen, canvas, paper, leather and wood.” [Jacquard, Cyanotype FAQs]

Something to print. An object that casts a shadow, a drawing on film, or a negative of a photograph. For a photograph, make a digital negative; a preview is on this site.

The steps

Mix the sensitizer. Follow the instructions that come with your chemistry. Jacquard’s kit describes it this way:
“Simply fill each bottle with water to create Stock Solutions A & B, and then mix the two in equal parts to create the cyanotype sensitizer.” [Jacquard, Cyanotype Kit]
Coat the paper, then dry it in the dark. Jacquard’s quickstart guide says:
“Coat the surface away from sunlight” [Jacquard, Cyanotype Kit quickstart guide]
“Allow to dry in the dark” [Jacquard, Cyanotype Kit quickstart guide]
And before exposure:
“Do not wet fabric or paper before or during exposure.” [Jacquard, Cyanotype Tips and Troubleshooting]
Lay your object or negative on top.
“Simply place the object on the sensitized surface and expose to sunlight (UV).” [Jacquard, Cyanotype Chemistry]
For a negative, the film has to lie flat against the paper; see the digital negative page.
Expose it to sunlight or UV. Jacquard’s kit page puts the whole step in one sentence:
“Coat the included Hahnemühle Platinum Rag Fine Art Paper with the sensitizer and, once dry, create prints by exposing to sunlight or UV (10-20 minutes, depending on conditions), using the included glass printing frame and objects or a film negative to create an image.” [Jacquard, Cyanotype Kit]
How long is the question everyone asks; the exposure time page sets out what the sources say.
Wash it.
“Rinse until water runs clear” [Jacquard, Cyanotype Kit quickstart guide]
“After exposure, prints are processed in a tray of cool water and allowed to air dry.” [Jacquard, Cyanotype Kit]
The Jacquard toning sheet adds an optional step:
“Submerging your washed print in a dilute bath of hydrogen peroxide after the initial wash will cause the blue to instantly reach its maximum intensity.” [Jacquard, Toning Cyanotype Prints]

If the print comes out pale, dark, blurry or yellow, see troubleshooting.

Safety

We give no handling advice of our own. These are the makers’ own words; read the data sheet of the product you buy.

The maker and the safety data sheets do not say the same thing. Jacquard calls its cyanotype chemistry non-toxic; the data sheet for ferric ammonium citrate calls it slightly hazardous by skin, eye, ingestion and inhalation, and the data sheet for potassium ferricyanide says the human health data is limited. All four are quoted here.

“Cyanotype is non-toxic and does not present any significant health risk or danger. That said, care should always be taken to avoid ingestion, inhalation and contact with skin when handling the cyanotype chemicals and fabrics.” [Jacquard, Cyanotype FAQs]

“Slightly hazardous in case of skin contact (irritant), of eye contact (irritant), of ingestion, of inhalation.” [Photographers' Formulary SDS, ferric ammonium citrate, green]

“Sensitive to light. Store in light-resistant containers.” [Photographers' Formulary SDS, ferric ammonium citrate, green]

“Information on the human health effects from exposure to this substance is limited.” [Photographers' Formulary SDS, potassium ferricyanide]

The potassium ferricyanide data sheet lists what it is incompatible with:

“Ammonia, chromium trioxide + heat, cupric nitrate, sodium nitrite + heat, acids and acid fumes.” [Photographers' Formulary SDS, potassium ferricyanide]

Preview a photo first

To see a photo as a Prussian-blue print before you coat anything, the free cyanotype preview turns it into a cyanotype look in your browser.

On your phone: Cyanotype

For iPhone and iPad.

The app shows your photo as a cyanotype print first, in seven looks, with print sizes and matte borders, so you can see the blue before you coat anything. Then it exports the digital negative at full resolution: black and white, inverted and mirrored, and for 4 × 5, 5 × 7 and 8 × 10 paper at the resolution that prints at the paper’s size. It all happens on the device. There is no account, and the app makes no network connections.

How this was checked

Statements about the process, its chemicals, safety and history are quoted word for word from the maker’s instructions (Jacquard), the Getty Museum and the Photographers’ Formulary safety data sheets, and linked where they appear (checked October 21, 2026). Where we could not fetch a source for a fact, we left the fact out, so this section gives no concentrations or amounts of chemicals: use the instructions and safety data sheet that come with what you buy. The digital negative tool is compared by an automated test with the Cyanotype app’s own code. If something here is wrong, tell us at a@noshu.net.