The two "mother and child" drawings have been sketched out in light pencil on regular drawing paper, thencolored in with oil pastels. Oil pastels are a great drawing medium because you have the accuracy of a pencil and the ability to smooth in colors like paint. "The swimmer from below" is an oil pastel on water color paper with no pencil sketch to help guide the lines.
"Falling Roses" is a composition taking the same rose and drawing it in different sizes. The background is cool colors while the roses are warm colors. The drawings where made to understand how warm and hot colors react when placing them next to one another. The same concept was applied to the yellow circles and red sphere.