I set up a still life of fruit for the kids to paint. They were able to add any kind of pattern to the "tablecloth", and any color to the fruit bowl. We used regular watercolor paints (Crayola 16-count Watercolors) for the painting. The painting and drawing took two days.
On the third day I had the students outline everything in black ink (washable black India ink) and I didn't even mind the inconsistencies in the thick/thin black lines around their fruit! I had them add a "cracked" stained-glass look to the background.