|Project by Scott||posted 01-14-2014 08:56 PM||1576 views||2 times favorited||4 comments|
I used the gum printing process to print a photograph onto a pine board. Gum printing is an old photographic process which was first done in the 1840’s, and uses gum arabic and ammonium dichromate as the light sensitive emulsuion. First you print a photo onto a transparency, then spread the emulsion on the substrate, which can be paper, cloth or wood. Finally, you place the transparency onto the emulsion and expose it to the sun for a couple of minutes, then wash it in warm water.
For this photo I used three colors and three individual exposures. To do color, you just create color separations in the software (split into RGB red,green,blue channels), then print 3 transparencies, one for each color. Then you use the opposite color with each transparency, so you use cyan or blue with the red one, magenta or red with the green one, and yellow with the blue one. Then just expose the red layer, wash it off and dry, expose green, wash/dry, expose blue and wash/dry.
The colors are somewhat muted because I chose to leave the wood grain showing. If you want brighter colors, you can use gesso which is essentially white paint that is used to ‘size’ the board. Then the colors can be snappier, more like the last photo which shows the same image which has been gum printed on white paper.
For more information on the basics about how to do it, see my one color project:
I made the frame from some old wormy pine, and finished it with stain and shellac.
-- Scott in North Carolina