Bernd Hutschenreuther shares how he enhances cyanotype prints by using a vacuum-sealed bag to press leaves or other materials tightly against the paper, ensuring sharp detail. Inspired by Lothmann’s experiments, this technique is practical for achieving high precision in botanical cyanotypes.
The main benefit of using a vacuum-sealed bag for cyanotype printing is achieving sharp, high-detail prints by ensuring perfect contact between the object (such as a leaf) and the sensitized paper.
The process
The process involves placing sensitized cyanotype paper inside a vacuum-sealable bag, positioning a leaf on top, and using a manual pump to remove air. This ensures close contact between the leaf and the paper, improving sharpness during UV exposure.
Materials Needed
- Aquarelle paper – such as Canson Montval – coated with cyanotype solution
- Leaves (fresh or dried)
- Vacuum-sealable bag (A5 size or larger such as these). Use manual vacuum bags that are reusable, a more sustainable option compared to disposable ones.
- Vacuum pump, such as this one
- UV light source (365 nm LED, or sunlight or the sun)
- Water for development
Step-by-Step Instructions
- Prepare the Bag – Place the cyanotype paper inside the vacuum-sealable bag with the blank side facing up.
- Position the Leaf – Lay the leaf onto the paper.
- Seal and Vacuum – Close the bag and use the pump to remove air, ensuring the leaf is firmly pressed against the paper.
- Expose – Place under a UV light or sunlight for the required exposure time (e.g., 5 minutes with a UV LED).
- Develop – Open the bag and rinse the cyanotype print in water to develop the image.
Further observations
- Leaves harvested in autumn (yellowed) can be used fresh or pre-treated to become parchment-like for enhanced transparency.
- Bleaching or extended exposure times may offer different effects.
- The method also works for flattening digital negatives for sharp prints.
If you read German, further details and images can be found here. If you try this, please let us know what you think by commenting below.
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Thank you very much for the comments. I got hints about the general method at the German forum https://forum.aphog.com/index.php?board/47-kreativtechniken/
It is interesting to get such bags without prints. I worked around by using larger bags for A4 format.
Other similar and larger bags are available for Bed linen, in other shops. The disadvantage: The valve is pushed strongly into the center. The advantage: They are rather large.
Great tip Isabelle, I took the liberty of inserting a link to what you mean. 🙂
little tip for finding those vacuum bags online, a little bigger, and without the label, is to look at the 3D filament printer area. They use those bags to store their filament.
It is nice when different people without knowing each other have a similar idea that works for small prints needing more crispness. I also had to use vacuum for my series Natural Textures, printed on a strongly textured cotton paper made by hand in India. I knew about the use of vacuum printing for large size negatives, and although mine was only a 20×30 cm size, it fitted the bags for vacuum sealing of my home foodsaver machine, I gave it a try and that was the final solution.
I wonder what type of experiments Mr Lothmann, his inspirator, was doing.