Prior to this lesson we did some value exercises. We folded our paper into four squares. We traced a smaller square of card board in the corner of each square and connected them with diagonal lines. We mixed different shades of gray by adding little dabs of black to small cups of white paint. We started with a light gray on the bottom of the shelf then added more black to mix a medium gray for the side and mixed a darker gray for the back of the shelf. While the shelves were drying students drew and colored objects to cut and glue onto them. Students were asked to think about the size or proportion of the object to the shelf.
**TIP- When I do color mixing or tinting in a lesson I like to give students a small cup (ketchup sized?) of white paint into which they mix the other color.