This was a fun lesson I did with my Grade 5 students that I found HERE. They learned the basics of proportion in a face. They practiced on scrap paper first, then drew their good copy on heavy 9 x 12" white paper. Then they outlined the face in Sharpie. Finally, they used bleeding tissue paper and cut it into squares. Using water and a paintbrush, they applied it to their paper, let it sit for a bit, then peeled it off to reveal the colour tranfer.