Last night we began our investigation of the characteristics of line beginning with contour line drawings. Contour lines define interior and exterior volumes. This is not outlining which only defines outside edges. Contour lines turn into the form whereas outlines continue along the outer edge of a form. Outlines are flat whereas contour line drawings are "plastic" or three-dimensional. "Accenting", allowing the line to be thicker/thinner or darker/lighter in areas, adds a greater sense of dimension. Although contour lines appear minimal, they can address subtle changes in a form's structure, color, value and texture all by means of accenting the line. This is evident is Colton's drawing above. One final note to remember: Dark lines advance, whereas light lines recede.