In line-drawing a very useful principle to observe, to give solidity to figures and objects, is to let one's lines—say of drapery or shadow—run into solid blacks in the deepest interstices of the forms, as when folds of drapery are wrapped about a figure, or in the deeper folds themselves (No. 1, p. [213]).
I have spoken of the graphic and the ornamental aims as distinct, and so they may for practical purposes be regarded; although in some cases it is possible to combine a considerable amount of graphic force with decorative effect, and even in purely graphic art there should always be the controlling influence of the sense of composition which must be felt throughout all forms of art.
For the simplest ornamental function, however, very little graphic drawing is needed, over and above the very essential power of definition by pure outline, and feeling for silhouette; but a sense for the relief of masses upon a ground or field, and of the proportions and relations of lines and masses or distribution of quantities, is essential. Now an ornamental effect may be produced by the simple repetition of some form defined in outline arranged so as to fall into a rhythmic series of lines.
A series of birds upon a plan of this kind, for instance, would form a frieze on simple bordering in abstract line alone, and might be quite sufficient for some purposes. The same thing would be capable of more elaborate treatment and different effect by relieving the birds upon a darker ground, by defining the details of their forms more, or by alternating them in black or white, or by adopting the simple principle of counterchange (see p. [215]).
