The summer has  gone, the sun’s UV levels are getting low, and it might be a good time to publish the results of my anthotype experiments…

Anthotype (plant print) is a printing method where images are made using plant juices. The juices of crushed petals, leaves or stalks are the photosensitive liquids, and they will also form the colors of the final prints. Basically you squeeze liquid out of the plant that has the color you want to use in your print. A paper is then coated with the plant juice, and exposed to sunlight — usually for a very long time!

A positive contact film is needed for the exposure — the process is based on fading of organic colorants. So, light will pass through the clear parts of the film (highlights), which will fade in the sun, and the dark parts will block the light, causing the shadows not to change much.

It is quite easy to make anthotype photograms, by exposing some opaque materials in contact with the emulsion. The tone scale will pretty much be like max density vs. fully faded material then; no intermediate tones. I was more interested in printing a real photographic scale… but, as it turned out, plant juices just are not really photographic emulsions, and their tonal range is somewhat limited. However, depending on a photographer’s intentions, anthotype can be a wonderfully expressive use of the photographic medium.

Anthotype images may not be very permanent, because any additional exposure to UV light tends to fade the print further. But then, this is an organic photographic process, changing like other organic matters too.  Permanence can be increased by a UV protection treatment — and keeping the print in the dark!

Jalo Porkkala: Leaf, anthotype.

Extract from Lily of the Valley, three coats applied with a foam brush on Canson Drawing paper. Exposure 7 hours. Covered with a UV protection spray and wax.

In my first experiment here I was using juice from leaves of Lily of the Valley (Convallaria Majalis), with a little bit added denatured alcohol — and I must say I was surprised at the speed of the lily emulsion; it took only about seven hours to expose the image seen above, in full sunlight. And that is super fast compared to the weeks or months exposures with some other plants. Due to this sensitiveness there may be a chance of this print fading pretty fast in natural light… to explore that I covered the print  with a UV protection spray (Print Guard), and moreover, waxed it with Renaissance Wax. The print is now going to be exhibited  for two months in a gallery illumination.