Gabriele Coassin shares a process which transforms cyanotype negatives into striking black-and-white silver prints. By contact printing in the darkroom, artists can achieve unique tonal effects, enhance contrast, and explore creative techniques like toning or liquid emulsion for further artistic expression.
WARNING: This is for experienced and advanced users only. Read the MSDS (Material Safety Data Sheet) before attempting to use chemicals and use the correct safety equipment. Hazardous chemicals are used.
How the Idea Was Born
The episcope is an old analog projector for non-transparent originals. By using it in reverse, I transformed it into a camera.
As a light-sensitive material, I used a cyanotype sheet, which produced the characteristic blue negative image.
By contact-printing the cyanotype onto photographic paper in the darkroom, I obtained a positive print. This process opened up artistic possibilities, some of which are showcased below.
So, can a cyanotype become a stunning black-and-white photograph? Yes!
Despite some initial difficulties, I refined the process and will simplify it here, focusing on the essentials.
The Starting Point
In the second half of the 19th century, printing negative plates or papers onto cyanotype became common. This blue-printing method, using iron salts, was a more affordable alternative to black-and-white printing with silver salts.
Here, we will do the opposite: starting with a medium-sized cyanotype negative to create a positive print on silver halide photographic paper or canvas.
Why Start with a Cyanotype?
Cyanotype images, particularly their unique transparencies and distortions, cannot be created with a traditional camera. These effects are only possible using the photogram technique, which reached its artistic peak nearly a century ago in black and white, later expanding into colour.
Among the most well-known classic photograms are Man Ray’s rayographs, created on negative photographic paper. Examples of his work are easily found online.
Illuminating the Cyanotype Transparently
At first, I experimented with a simple and inexpensive LED light tablet, commonly used by children for tracing. I typically use this device to backlight negatives, plates, or slides before printing or digitizing.
However, two key issues made the tablet unsuitable for this process:
- Frame Thickness: The thin millimeter frame prevents uniform pressure when placing sheets under standard-sized glass. A possible solution is to use a smaller piece of glass or cut one to fit precisely, ensuring the edges are smoothed to avoid injury.
- Inconsistent Light Control: The tablet cycles through brightness levels with each press of the button: low → medium → high → off. This makes exact exposure timing impossible. In my tests, thin cyanotype sheets required 1–2 seconds at low light, while heavier 300–350g sheets needed 3–4 seconds.
To resolve the frame thickness issue, I considered purchasing a frameless light board. Larger models up to A2 size are available, but cheaper versions often have a dotted texture that imprints onto the image.
Placing a sheet of plain printing or baking paper on top helps, but overall, the setup proved too complicated.
Here you can see the curvature of the paper not pressed under glass.
Darkroom Setup
First, prepare the darkroom with basins, properly diluted chemicals, and ensure everything is at the correct temperature.
I will not detail this process, as there are countless tutorials available. For Italian beginners, my articles on the darkroom, published in Tutti Fotografi (Nov–Dec 2023 and Jan 2024), are accessible on Fotografia.it.
Recommended Procedure
The cyanotype negative must be free from writing or labels on the back, as these may appear in the final print due to transparency.
To expose photographic paper in the darkroom, I use either a controlled light source from a photographic enlarger or a small, vertically hanging lamp of a few watts.
For optimal results with variable contrast photographic paper, I recommend a directional spotlight with a warm color temperature (approximately 2700K).
To ensure even illumination, place the light source at a distance three times the diagonal of the sheet. For example, an A4 sheet has a diagonal of 36 cm, so the spotlight should be positioned about one meter away.
Exposure and Development
Once the room is completely dark, turn on only the red safelight, ensuring it is at least 120 cm away from all areas where the sensitive paper is handled.
Before making the final print, perform exposure tests using small strips of photographic paper (one-quarter the size of the final sheet).
To ensure the cyanotype negative stays in contact with the photographic paper, place it under a heavy, well-cleaned glass plate.
Position the cyanotype with the image facing down onto the glossy, light-sensitive side of the photographic paper (e.g., Ilford Multigrade or Foma Variant).
After pressing the materials under glass, expose the print and develop test strips to determine the correct exposure time. Once the optimal density is achieved, proceed with the final print.
Excitingly, the resulting positive image has a striking graphic effect. However, the texture of the cyanotype paper will be subtly visible in the final print.
Enhancing Contrast
If the contrast is too low, use a purple/magenta filter in front of the light source. Be sure to block any stray light escaping around the filter.
This adjustment will increase the required exposure time by 20–30%, but the improved graphic effect is worth it.
Alternatively, use a photographic enlarger with multigrade filters or a color head to refine contrast control.
For the Advanced Artist: Toning
To further enhance the final print, consider toning.
You can use commercial chemical toners, such as VIRSEP Bellini, though these can be expensive. Natural alternatives like black tea provide a more cost-effective and permanent solution.
Instructions for various toning techniques can be found in classic manuals and online tutorials, particularly in the AlternativePhotography.com resource.
Exploring Liquid Emulsion
For an even more advanced approach, consider using liquid emulsion combined with silver nitrate.
In long-term workshops, I apply this technique by coating canvas with fine-art cementite before sensitizing it.
Since the full process of preparing and handling liquid emulsion is complex, I will not detail it here. Those interested can learn more about liquid emulsion here.
but the results are of absolute value and great effect.
Want to Try It Yourself?
Keep in mind that contact printing does not allow for enlargement. If you want a large-format positive print, your original cyanotype negative must be the same size as the final print.
In the case of the framed print shown here, the final positive is a cropped central portion of a 56×76 cm cyanotype, leaving out the edges, which would otherwise appear black.
The artworks are © Rita Mungiardi, Treviso, Italy 2022-25.
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