Here at Mecca in Eugene, OR, I am teaching a Collagraph class. Here are some examples of what can be achieved with the process.
The original collagraph matrix- a eugene landscape. I taped and glued elements to the surface and carved away with an exacto blade.
A black relief print.
a color relief print, I put blue (straight out of the tub) on the top and mixed a green on the bottom.
A colored pencil rubbing of my matrix. (notice, it is not reversed.) I put in a sunset and little cars on the bridge.