Introduction to Cyanotype Printing

Cyanotype printing is a photographic printing process that produces a cyan-blue print. Engineers, botanists, and artists have used this technique since its development in the 19th century by Sir John Herschel.

Anna Atkins, an English botanist, is often credited with popularizing the process in her documentation of algae. The process involves the use of two chemicals, ferric ammonium citrate and potassium ferricyanide, which react to light to create beautiful, intricate blueprints.

Step-by-Step Guide to Cyanotype Prints with Botanicals

Materials Needed:

• Cyanotype chemicals - Ferric ammonium citrate and potassium ferricyanide

• Water

• Brushes or foam brushes

• Watercolor or heavy paper (e.g., Arches, Fabriano)

• Glass or acrylic sheet

• Flowers/botanicals

• Sunlight or UV light source

• Gloves and apron (for safety)

• Trays or containers for rinsing

• Hydrogen Peroxide (for faster oxidation)

• Clips or weights (optional)

Steps

1. Prepare Your Workspace

   • Ensure you are in a dimly lit room to prevent premature exposure of the cyanotype solution.

   • Wear gloves and an apron to protect your skin and clothing.

2. Mix the Cyanotype Solution

   • In a dimly lit area, mix equal parts of ferric ammonium citrate and potassium ferricyanide with water. Use separate containers for each chemical, then combine them in a third container to create your sensitizer solution.

3. Coat the Paper

   • Using a brush or foam brush, evenly coat your watercolor or heavy paper with the cyanotype solution. Ensure the paper is fully covered but avoid pooling.

   • Allow the paper to dry in a dark place. This can take a few hours or overnight. You can also use a hairdryer on a low setting to speed up the process.

4. Arrange Your Flowers/Botanicals

   • On a flat, protected surface, place your dried, sensitized paper.

   • Arrange your flowers or botanicals on the paper. You can experiment with different compositions to achieve the desired effect.

5. Exposure

   • Carefully place a glass or acrylic sheet over your arranged flowers to hold them in place and ensure good contact with the paper.

   • Expose the setup to sunlight or a UV light source. Exposure time can vary depending on the intensity of the light and weather conditions but typically ranges from 10 to 30 minutes. You will see the paper change color from greenish-yellow to a dark blue

6. Rinse the Print

   • Once the exposure is complete, remove the flowers/botanicals and rinse the print in running water for about 1-10 minutes to wash away any unreacted chemicals.

   • The print will continue to develop and darken during the rinsing process. You may add some hydrogen peroxide to expedite the oxidation.

7. Dry the Print:

   • Allow the print to dry flat in a shaded area. You can use clips or weights to prevent curling.

   • Once dry, your cyanotype print is ready!

Tips for Successful Cyanotype Prints

Experiment with Exposure Times - Different light sources and weather conditions can affect the exposure time. Experiment to find the best results for your environment.

Use Fresh Flowers/Botanicals - Fresh, pliable flowers and leaves tend to create more defined prints compared to dry or brittle ones.

Create Test Strips - If you are new to cyanotype printing, create small test strips with varying exposure times to understand how the process works before committing to a larger piece.

Enjoy creating your beautiful, nature-inspired cyanotype prints!