Values are determined by the lighting conditions (i.e. source, time of day, etc.) as well as the planar structure of the objects. Most artists use value to address the volumes of forms as well as the lighting conditions but some artists will emphasize the light patterns over volume. To do this, artists will employ a mark-making technique that contradicts volume capturing and focusing on the juxtaposition of dark and light values. The drawings here show a single directional hatch technique and the scribble technique.