I just finished the last drawing for Desk Top Drawings Phase 3. This is a series of drawings on photos that began as doodles on my work desk. So Phase 1 is photographs of the doodles on the work desk. Phase 2 is photos of the doodles that I have drawn on top of. Phase 3 is photos of phase 2 that I have drawn on top of again. Next I'll start phase 4, drawings on top of a photo of a photo of a photo of a photo.
This is a very simple system, but in practice it combines the process of redefining an image while the image is being degraded by photographic reproduction.