Imagine capturing shadows and light, not with a camera sensor, but with the sun itself, painting surfaces in stunning shades of deep Prussian blue. This is the magic of cyanotype printing, a wonderfully accessible photographic process dating back to the mid-19th century. It’s often called “sun printing” for a good reason – ultraviolet light is the key ingredient that transforms chemically treated paper or fabric into unique, monochrome artworks. Unlike many complex photographic techniques, cyanotype offers a relatively simple entry point into the world of alternative processes, allowing anyone to create beautiful, one-of-a-kind prints using little more than sunlight, water, and a few special chemicals.
The distinctive blue hue is instantly recognizable. It’s a process born from scientific discovery but embraced by artists and crafters for its versatility and ethereal aesthetic. Whether you’re preserving the delicate outlines of leaves and flowers found on a nature walk or transferring intricate photographic negatives onto textured paper or wearable textiles, cyanotype provides a direct, hands-on connection between the artist, the subject, and the fundamental power of light.
A Glimpse into the Blue: How it Works
At its core, cyanotype relies on a photosensitive solution made from two iron compounds: ferric ammonium citrate and potassium ferricyanide. When these are mixed (usually with water) and coated onto a surface like paper or natural fabric, they don’t react much in dim light. The real transformation happens when this coated, dried surface is exposed to a source rich in ultraviolet (UV) light, most commonly the sun. The UV rays trigger a chemical reaction, reducing the iron compounds into an insoluble blue pigment known as Prussian blue (ferric ferrocyanide) precisely where the light strikes. Areas shielded from the light, perhaps by an object like a leaf, a feather, or a photographic negative, remain unexposed.
After sufficient exposure, the print is developed simply by washing it in plain water. The water rinses away the unreacted, water-soluble iron salts from the shielded areas, leaving behind the stable, brilliant blue image where the light worked its magic. The result is a negative image: areas exposed to light turn blue, while areas blocked from light remain the original color of the substrate (usually white or off-white). This simplicity is a huge part of its charm – no darkroom enlargers or complex developing agents are needed.
Gathering Your Sun Printing Supplies
Getting started with cyanotype printing is less daunting than you might think. Many suppliers offer convenient pre-mixed kits containing the two chemical parts in liquid or powder form, ready to be combined. Alternatively, you can purchase the individual chemicals, ferric ammonium citrate and potassium ferricyanide, and mix them yourself following specific recipes (though kits are highly recommended for beginners).
Essential Materials:
- Cyanotype Chemicals: Either a two-part kit or the individual components.
- Surface to Print On:
- Paper: Heavyweight, absorbent papers work best. Watercolor paper (hot or cold press), printmaking paper, or even thick cardstock are good choices. Avoid glossy or heavily coated papers.
- Fabric: Natural fibers like cotton, linen, silk, or hemp are ideal. Synthetic fabrics generally don’t absorb the solution well. Always pre-wash fabrics to remove any sizing or finishes.
- Brushes or Coaters: Soft foam brushes or traditional hake brushes work well for applying the solution evenly. Sponge rollers can also be used, especially for larger areas.
- Mixing Containers: Non-metallic containers (glass or plastic) for mixing chemicals if not using a pre-mixed solution.
- Measuring Tools: Spoons or graduated cylinders if mixing from raw chemicals.
- Trays: Plastic or glass trays larger than your print size for washing.
- Water Source: Access to running water for rinsing prints. Distilled water can sometimes yield slightly clearer results for the initial mix if your tap water is very hard.
- UV Light Source: The sun is the traditional and most accessible source! Alternatively, a UV lamp or exposure unit can be used for more controlled and consistent results, especially on overcast days or for indoor work.
- Objects or Negatives: Anything that can cast a shadow or block light: leaves, flowers, lace, feathers, stencils, drawings on transparency film, photographic negatives (digital negatives printed on transparency film work great).
- Glass or Acrylic Sheet: To hold objects flat against the surface during exposure, ensuring sharp details. Clips or weights might also be needed.
- Gloves and Protective Gear: Disposable gloves are recommended when handling the chemicals. An apron is also a good idea.
- Drying Area: A dark or dimly lit space where coated materials can dry completely, undisturbed. A clothesline or drying rack works well.
Creating Cyanotypes on Paper: Step-by-Step
Printing on paper is often the best starting point for newcomers to cyanotype.
1. Preparation: Work in subdued light, away from direct sunlight or UV sources. If using a kit, follow the instructions to mix the Part A and Part B solutions, usually in equal volumes. If mixing from scratch, carefully measure the chemicals according to your chosen recipe and dissolve them in water.
2. Coating the Paper: Place your paper on a protected surface. Dip your brush into the mixed cyanotype solution and apply it evenly across the paper. Aim for a smooth, consistent coat without puddles. You can coat the entire sheet or create specific shapes or borders. The solution will likely appear yellowish-green.
3. Drying: Transfer the coated paper to a dark place to dry completely. This can take anywhere from 30 minutes to a few hours, depending on humidity and paper thickness. A hairdryer on a cool setting can speed things up, but air drying is generally best. The paper must be bone dry before exposure.
4. Composition: Once dry, take your paper (still in subdued light) and arrange your chosen objects (leaves, lace, etc.) or negatives directly onto the coated surface. If using objects, consider how their shapes and opacity will translate. For sharp images, place a sheet of glass or acrylic over the arrangement to press everything flat against the paper. Secure with clips if needed.
5. Exposure: Carefully take your setup out into direct sunlight or place it under your UV lamp. Exposure times vary greatly depending on the strength of the UV light (time of day, season, cloud cover) and the density of your objects or negative. It could range from 5 minutes on a bright summer day to an hour or more on an overcast day or with a weak UV lamp. The coated area will typically change color during exposure, often shifting from yellow-green to a bronze or greyish-blue. Experience and test prints are the best guides here.
6. Washing (Development): Bring the exposed print indoors, remove the objects/negative and glass. Immediately place the print into a tray of cool running water. Gently agitate the print in the water. You’ll see the unexposed yellow-green chemicals wash away, while the exposed areas transform into a vibrant Prussian blue. Continue washing for at least 5 minutes, or until the water runs clear. Some recommend a final rinse in water with a splash of hydrogen peroxide to rapidly intensify the blue, but this is optional – the blue will naturally deepen as the print dries and oxidizes over 24 hours.
7. Drying the Final Print: Carefully remove the print from the water and hang it up to dry, or lay it flat on a clean screen or absorbent surface. Paper prints may curl; they can be flattened under heavy books once completely dry.
Adapting the Process for Fabric
Cyanotype on fabric follows the same basic principles but requires a few adjustments.
1. Fabric Preparation: It’s crucial to start with clean, natural fabric. Machine wash and dry the fabric (cotton, linen, silk) without fabric softener to remove any sizing or treatments that could interfere with the chemical absorption. Iron the fabric smooth.
2. Coating: Applying the solution evenly on fabric can be trickier than on paper. You can use a brush, sponge, or even dip the fabric (though this uses more solution). Ensure the fabric is saturated but not dripping excessively. Work the solution into the fibers.
3. Drying: Hang the coated fabric in a dark place to dry completely. This usually takes longer than paper. Again, ensure it is thoroughly dry before proceeding.
4. Composition and Exposure: Arrange your objects or negatives as you would on paper, using glass to keep them flat. Fabric generally requires longer exposure times than paper due to the way the fibers absorb light and chemicals. Be prepared to experiment.
5. Washing: Fabric needs a very thorough rinse to remove all unexposed chemicals trapped in the fibers. Rinse under running water, gently agitating, until the water runs completely clear. This might take 10-20 minutes or longer. Incomplete washing can lead to yellow staining later.
6. Drying and Setting: Hang the fabric to air dry. Once dry, the blue color will continue to deepen over the next day or so. Heat setting with an iron (on the appropriate setting for the fabric type, usually dry heat) can help improve the wash-fastness of the print, though cyanotypes on fabric may still fade slightly over time with repeated washing. Wash finished items gently in cold water.
Handling Chemicals Safely: While cyanotype kits are generally considered low-toxicity for photographic processes, always exercise caution. Wear gloves when mixing and applying the solution to avoid skin contact and staining. Work in a well-ventilated area, especially if mixing from powder chemicals, to avoid inhaling dust. Never ingest the chemicals and keep them away from eyes, children, and pets. Label all containers clearly.
Exploring Creative Cyanotype Techniques
The basic process is just the beginning. Cyanotype offers a vast playground for experimentation:
- Photograms: Using opaque or semi-transparent objects to create silhouette images. Layering objects can create interesting depth.
- Digital Negatives: Print black and white images onto transparency film using an inkjet printer to create detailed photographic cyanotypes. Remember to invert the image before printing the negative!
- Wet Cyanotype: Spritzing the print with water or other liquids (like vinegar or soapy water) during exposure can create unique textures, bleeds, and diffusion effects.
- Toning: After washing and drying, cyanotypes can be toned using common household items like strong black tea, coffee, or wine tannin to shift the blue color towards brown, purple, or grey tones. This requires further rinsing.
- Double Exposure: Expose an image, wash partially or fully, then rearrange objects or add a second negative and expose again before the final wash.
- Fabric Manipulation: Try cyanotype on clothing, tote bags, quilts, or scarves. Use resists like wax or masking fluid before coating to create patterns.
Tips for Achieving Great Sun Prints
- Test Strips: Always make test strips with new paper/fabric or uncertain light conditions to determine the optimal exposure time.
- Consistent Coating: Strive for an even application of the sensitizer to avoid blotchy prints.
- Dryness is Key: Ensure the coated material is completely dry before exposure; dampness can cause blurry results.
- Secure Your Composition: Wind can easily disturb lightweight objects outdoors. Use glass and clips to keep everything firmly in place.
- Thorough Washing: Don’t skimp on the final wash. Residual chemicals can degrade the print or cause staining over time.
- Embrace Imperfection: Part of the beauty of cyanotype lies in its handmade nature. Slight variations and unexpected results are part of the process.
Cyanotype printing is a captivating blend of science, art, and nature. It encourages observation, patience, and experimentation. The process of coating a surface, arranging elements under the sun, and watching the image emerge in the water bath is deeply satisfying. Whether you’re creating delicate botanical studies on paper or bold graphic designs on fabric, sun printing offers a unique way to leave your mark, powered by light itself. So gather your materials, wait for a sunny day (or switch on your UV lamp), and dive into the beautiful blue world of cyanotype.
