Slow photography

A gum print is made with an emulsion of three components; gum Arabic, a dichromate and a pigment. The papers used are usually 100% cotton so that they can withstand some abusive treatments; being wet for long times among others. The emulsion is spread on a prepared (pre-shrinked and sized) paper with a brush. After the paper has dried, a negative the size of the print is laid on the emulsion-side of the paper after which it is exposed to a UV light source. The light will harden the dichromate-gum Arabic-pigment mixture to the degree of UV exposure received. The paper is developed is plain water where the unhardened (the highlights of the print) will wash away. Developing time can be as long as two or three hours. Then the print is dried and one can decide to make another layer. When making three or four colour prints this procedure has to be repeated with a different negative for each colour. Some gum-printers choose to make very 'thin' layers, so they can control colour better. There are printers who make prints with up to 16 layers. Although I am not one of them, I do often make more than four layers in a colour print.

So the basics seem quite simple; three ingredients and a good paper. But after working with this process for quite some time now I have discovered that in fact it is quite complex. And I am not alone when I say that this is a very seductive process. It is very labour intensive, and there is definitely a meditating aspect at being busy with making prints the slow way.