Students drew self-portraits yesterday. Marina's drawing above is a good example of how bone structure and planes influence value and gradations. Depth is achieved by establishing a strong core shadow on the left side of the face. More importantly, there are alternating dark and light areas moving vertically down the face starting with the forehead to the eye sockets then the nose, under the nose leading to the mouth and under the lip and lastly the chin and the neck. It is crucial to address these "peaks and valleys" within the topography of the face in order to create a three-dimensional, volumetric portrait. There are no flat areas on the face; the surface is constantly changing.