How to Use a Cyanotype Kit | Developing Blue Prints

A cyanotype kit turns sunlight into deep blue photographs and shadow prints using two iron-based chemicals that react only to ultraviolet light. The process is forgiving, needs no darkroom, and suits beginners making botanical prints, photograms, or contact prints from digital negatives. Here’s the full workflow and the mistakes that ruin prints.

What Comes In The Kit And How To Mix It

Most kits ship two separate bottles of light-sensitive chemicals, labeled A and B. The Jacquard Cyanotype Kit booklet directs you to fill each bottle with water, shake well, and wait 24 hours for full dissolution before mixing equal parts A and B to make the sensitizer.

Mix only as much as you’ll use soon. Per the Jacquard booklet, the mixed sensitizer stays stable only for several hours; Bostick & Sullivan advises using mixed chemistry within 24 hours, while When in doubt, mix fresh.

• Combine equal parts A and B in a small dish.
• Stir thoroughly — unmixed streaks show up as uneven tones.
• Wear plastic or latex gloves; the chemistry can stain skin and fabric.
• Mix under low light, away from windows.

Coating happens in subdued lighting since the solution reacts to UV only. Bostick & Sullivan’s instructions say a safelight isn’t necessary and normal room lighting is fine, but recommends a windowless room or shaded windows while working.

How Much Solution Does Each Print Size Need?

Coating the paper is straightforward with a brush. The Jacquard booklet specifies its included Hake Brush, while Flic Film directs a foam brush. For precise chemistry amounts,

Cyanotype is compatible with more than paper. The Jacquard booklet lists paper, fabric, wood, leather, and canvas as suitable surfaces. Brush the sensitizer on evenly, then let the coated surface dry in a dark area — If you coat several sheets at once, store the extras in a dry, dark place for later exposure.

Exposure And Development Steps

Once dry, the coated surface is ready for printing. Lay flat objects like leaves, lace, or negatives directly on the coating, then place a sheet of glass over everything to keep items pressed tight against the surface. The Jacquard booklet includes a digital-negative workflow: convert your photo to black and white, invert it to a negative in editing software, and print it on the provided SolarFast Film.

Take the arranged print into direct sunlight or under a UV lamp. Jacquard’s exposure guidance is 10–20 minutes in sunlight, continuing until the exposed areas turn bronze. That bronze tone is the visual cue that exposure is complete — stopping early is the most common cause of weak, washed-out prints.

Development is nothing more than a water rinse. Follow these steps:

1. Remove the objects or negative from the coated surface.
2. Rinse the print under running water for at least 5 minutes, changing the water periodically until it runs clear —
3. For deeper blues, optional: bathe the print in a 3% hydrogen peroxide solution for 60–90 seconds, then wash 8–10 more minutes.
4. Hang the print to dry away from direct sun; the blue deepens as it dries.

After washing, the image is safe to view in daylight.

Common Mistakes That Ruin Cyanotype Prints

Each culture of cyanotype printing has classic failure points, and most trace back to light, chemistry, or patience. Fogged, muddy prints come from coating or drying in bright light — that UV sensitivity works against you before the print is made. Work in that windowless room or shade the windows.

Underexposure produces pale, low-contrast prints. Trust the bronze color over the clock; overcast days need longer exposure than full sun. Incomplete washing leaves yellow-brown stains that appear only after drying, so when in doubt, rinse longer. Chemistry left sitting in its mixed state degrades, and the safest habit is mixing only what the afternoon’s printing session needs.

Handling the solutions calls for basic caution. Bostick & Sullivan recommends plastic or latex gloves while mixing, coating, and processing. The chemistry can irritate skin and eyes on contact, so wash any splashes off promptly.

For those ready to buy their first kit, our tested roundup of the best cyanotype kits breaks down which bundles include paper, brushes, and film for the smoothest start.