I like to do this leaf printing project in the fall. I ask students to bring in leaves and I bring in some from home. We classify each leaf. With third graders, I talk about mixing the paint right on the leaf to get intermediate colors. I use tempera paint cakes and tell my students to keep the paint on the dry side. Paint the side of the leaf with the veins, turn the painted leaf over onto paper and rub with a paper towel to get a good print. Lift the leaf off.