Gumoil was invented in 1990 by Karl Koenig. He discovered that if he made a print of non pigmented gum arabic, he could then paint over it with oil paint and create an image. He based this of a popular darkroom technique called bromoil. With bromoil, a darkroom print is created and then bleached out creating was is called a matrix. The artist then uses ink to bring back the blacks. The results are generally contrasty, but much more painterly looking than a normal darkroom print.
With gumoil, no bleaching of the print is necessary. I take gum arabic, a byproduct of the acacia tree, and mix it with ammonium dichromate which makes it sensitive to UV light. I then brush the mixture onto a 100% cotton paper, let it dry, and then it expose it with my negative under UV light (for what my exposure unit looks like, see the previous post!). The result is a gum matrix. For gumoils compared to every other process I work with, my negative is actually a positive. When you expose an image, the dark parts of the negative turn out white, the clear parts turn out dark. This is the same concept, except because it is a positive, the resulting image will be a negative. What I essentially did was create an image of the white parts of the final piece. The paint will become the midtones and blacks.
Once I have created a matrix, it is ready for paint. I use oil paint, currently I've used both M. Graham and Windsor and Newton paints in lamp black, but I have seven other brands on the "to try" list. I paint a layer of black over the matrix, let it sit until the areas that need to be black are no longer shiny, and then rub the print with paper towels. This lifts up the excess paint and the gum arabic parts start to show through.
I let the print dry for about 15 minutes before I then put it in a tray of water. For the first layer, I let it sit in the water for about a minute, and then brush anymore excess paint off with a fine bristle brush. After the print is dry, I'll assess it. If there is enough gum left, I'll do another layer of paint and rubbing. With this second layer, I'll put it in a bleach solution after I have let it dry for a bit. The bleach helps to eat away any paint that may be causing some "muddying" of the image. The result is a print that shows the texture of the paper, the texture of the paint and gum, and creates a very painted look while being a completely photographic process.
|Three matrices ready for paint.|
|Two prints in the middle of the rubbing process|
Here are the results of my paper testing. My goal with this was to determine which papers I liked best and which papers took to the process the best. I found that while I personally liked the smoother finish papers, the process tended to take to the more textured paper with two exceptions, both from Fabriano. A different gum mixture and exposure could make the smoother papers better, and that is something that I can explore in more depth now that I know how the papers handle the process.
The image is called Hidden Oak, and if you recall from the previous post, this is the image that was shown in the Visual Art Exchange in Raleigh, NC. For that particular print, the second paint color was terra rosa, and like most of my favorite images, was a total accident.
|All of the papers laid out and labelled|
|Close up of the prints|
|Close up of the prints|
|The best one from the first round of experimentation: Fabriano Acquarello |
Hot Press, two layers of paint.
|Hidden Oak in the VAE!!|