Combining Cyanotypes, Chemigraphs and Transparencies. Part 4

In part 4 of our cyanotype series, Caroline Roberts continues her exploration of chemigraphs – abstract cyanotypes created through chemical reactions – by combining them with transparencies. Building on her previous articles, she experiments with how different drying and exposure methods affect the final image. Roberts compares results from outdoor and UV-unit exposures, revealing surprising variations in tone, blending, and contrast. Through detailed testing, she discovers that dried chemigraphs paired with high-contrast transparencies produce striking, moody results, expanding the creative possibilities of cyanotype printing.

Writer and photography / Caroline Roberts

Read the MSDS (Material Safety Data Sheet) before attempting to use chemicals and use the correct safety equipment.

This article follows on from Introducing Chemigraphs: Abstract Cyanotypes with Added Chemistry – I advise reading that article first to get an overview of the process. While I was working with chemigraphs, it didn’t take many rainy days in a row for me to wonder if I could:

1. lay out a chemigraph, let it dry, before exposing it in a UV unit.
2. expose a chemigraph in a UV unit

Spoiler alert: both of these options work, but they give different results to an outdoor exposure.
Taking these two options separately, let’s look at what happens.

Option 1, letting the chemigraph dry (in the dark) before exposure

Letting the chemigraph dry before exposure in a UV unit gives startlingly different results from the outdoor exposure. As might be expected, the chemicals blend during the drying process and give much softer results. The difference I did not expect is that, despite the same quantity of chemicals being added to the paper, the final print is significantly lighter.

There are a couple of advantages to doing this. Coating can be done on completely level surfaces, and the paper does not need to be moved until fully dry. Additionally, you can use simple, high-contrast transparencies on the dried surface. It is this combination process that I am going to cover in this article.

Option 2, exposing a chemigraph in a UV unit rather than outside

Exposing a chemigraph in a UV unit requires a very long exposure time since the paper has to dry as well as expose. This extended exposure time makes the indoor exposure very inefficient (5.5 hours for my unit, over 2 hours outside). The slower drying also meant that the chemistry had time to blend together, but the end result was not what I expected. I anticipated something close to the dried then exposed result, but despite the longer wet time, the chemistry does not blend as much.

Step-by-step process for a dried chemigraph with transparency

1. Soak your paper, submerging it fully in clean water for 10-15 minutes.
2. Briefly blot the paper to remove excess water.
3. Put the paper on a flat surface where it can stay for the full drying time. Use a hake brush to coat the paper. The exposure surface needs to be as level as possible to avoid runoff, but some pooling of solution is inevitable.
   Use any dilution and ratio of Potassium Ferricyanide and Ferric Ammonium Citrate that you want; however, I recommend stronger solutions – the standard 20/8, for example – since the resulting exposure will be much lighter than you might expect.
4. Add the additional substances – water spritzes, salt, rubbing alcohol, and washing soda.

   

5. Let the paper dry in an area that is either dark or very dimly lit.
6. Once the paper is completely dry, brush off any loose salt, soda crystals etc.

   

7. Place your transparency and sandwich the paper and transparency in a clip frame. I use a simple glass clip frame with some felt to improve the contact and large binder clips to hold everything together.

   

8. Expose for the same time as you would expose any other transparency, either outside or in a UV unit.
9. Wash and dry completely.
   Dilutions I used for these examples and notes on what works well.
   Since the chemigraphs that are dried before exposure come out much paler than expected from the wet versions, stronger solutions give better results with a transparency. For this article, I tested the following dilutions: 20/8 (20g/100ml A; 8g/100ml B), 10/10 (10g/100ml A; 10g/100ml B), and 30/8 (30g/100ml A; 8g/100ml B). There was not a massive difference in the end results, apart from some crystallization speckling on the 10/10 example.

   

    

   

   

   I tested this process with three types of transparency: a text positive (no tonal variations, just black and white), A Vandyke Brown negative (high contrast), and a traditional exposure cyanotype negative (low contrast).
   I would not recommend using detailed photographic transparencies with this process; the contrast range is very low, and, despite brushing off the added salt, it was hard to get perfect contact between the negative and the coated paper.

   

   The higher contrast Vandyke Brown negative gave a moodier image and definitely has some potential.

   

   The results from using a positive text transparency have the most clarity, as well as gaining interest from the uneven ground.

   

This process has potential when used with high contrast imagery, such as drawings or very contrasty negatives, or with text positives. The variability in the dried chemigraph adds interest and moodiness to the final image.
In the next article, Cyanotype Layering: Chemigraphs Followed by Contact Prints. Part 5 we will look at layering chemigraphs with contact printing using double exposures, looking at some of the pitfalls and coming up with some solutions.

The 5-part experimental cyanotype series

In this 5-part experimental cyanotype series, Caroline Roberts explores how variations in dilution, exposure, and moisture can expand the creative potential of cyanotypes. Based on her research and studio practice, the series focuses on material and process-based experimentation beyond traditional methods.

• Part #1 – Going Beyond Blue to Explore Cyanotype Variables: Dilution, Exposure, and Moisture – introduces her initial experiments – systematically varying wet, dry, and soaked paper conditions, as well as chemistry dilution and exposure settings – to establish a base for further testing.
• Part #2 – Working Wet: Techniques and Effects in Super-Wet Cyanotypes – explores what she calls the “super-wet” cyanotype: highly fluid chemistry used to create photograms with differing object weights and absorbency, but without adding other chemicals.
• Part #3 – Introducing Chemigraphs: Abstract Cyanotypes with Added Chemistry – focuses on chemigraphs – abstract works created by introducing reactive materials to the cyanotype mix, altering colour and texture during exposure and development.
• Part #4 – Combining Cyanotypes, Chemigraphs and Transparencies – details her process for combining dried chemigraph surfaces with simple transparency overlays, particularly text-based elements used in her publications Memoranda and Daybook.
• Part #5 – Cyanotype Layering: Chemigraphs Followed by Contact Prints – looks at combining these approaches – layering chemigraphs and transparency cyanotypes through multiple exposures and different coatings – to create complex, multi-process images.

This series is both a visual record and a technical resource for artists working with cyanotype, offering practical insights and encouraging further material investigation. To get notified when cyanotype articles are published, subscribe to the Cyanotype Newsletter.

Caroline Roberts, with a background in Chemical Engineering and an MFA in Painting, creates experimental, camera-less work exploring nature and climate. Her art has been widely exhibited and supported through residencies at BOX13, The Printing Museum, and Penland.