106. Outlines are lines which, returning to themselves, make inclosures
and describe areas of different measures and shapes. What has been
said of lines may be said, also, of outlines. It will be worth
while, however, to give a separate consideration to outlines, as a
particularly interesting and important class of lines.
As in the case of dots and lines, I shall disregard the fact that the
outlines may be drawn in different tones, making different contrasts of
value, color, or color-intensity with the ground-tone upon which they
are drawn. I shall, also, disregard possible differences of width in
the lines which make the outlines. I shall confine my attention, here,
to the measures and shapes of the outlines and to the possibilities of
Harmony, Balance, and Rhythm in those measures and shapes.