The most recently invented alternative photo process is gumoil printing. The late Karl Koenig developed it in the 1990s. It involves hand paining a gum arabic/sensitizer solution onto a cotton rag paper and exposing it with a positive transparency. After a water wash, a negative gum impression remains on the paper. Next, oil paint is applied and then slowly rubbed back off, rendering a photographic image. Bleaching and recoating with a second color can further enhance it. It is a very labor-intensive and unpredictable process, but the reward is a very painterly image with a rich polychrome oil color.
"I love the challenge of this process. When you get it right and the image is emerging from the oil paint, clearer and clearer the more you rub it, it feels magical. There are a lot of surprises and corrections that can be done with this process. It's great if you like to experiment with prints because there are so many stages in making the print, each one changing the look completely. Let's just say I don't get very many finished prints when I delve into printing gumoils, but when I do the result is very satisfying and unique."