In graphic drawing, lines to express forms in the relief of light and shade are often needed to give additional force even where no great degree of realism is desired. A tint formed by horizontal lines is sufficient to relieve a face from the background and give it solidity, while local colour may be given to the hair, and at the same time serve to relieve the leaves of a wreath encircling the head (see illustration, p. [178]).
The rich effect of clustered apples growing among their leaves could hardly be suggested without the use of lines expressive of light and shade, the interstices of the deepest shade running into solid black (p. [178]). In adding lines in this kind of way to give relief or extra richness or force, the draughtsman is really designing a system of lines upon his outline basis, which may have quite as decorative a quality as the outline itself. At the same time nothing is more characteristic of the artist than the way in which such lines are used, and of course the choice of direction and arrangement of such lines will make all the difference in the effect of the drawing.
Diagonal Shading
Where the object is to express the figure in broad masses of light and shade, the use of a series of diagonal lines is an effective, and probably the most ready and rapid, method when working with the pen (see p. [179]). This system of expressing the broad surfaces of shade was much used by the Italian masters of the Renaissance in their rapid pen sketches and studies of figures, and a certain breadth and style is given to their drawings owing in part to the simplicity of this linear treatment.
Emphasis
No doubt the simpler the system of line adopted in giving relief to figures the better, if the particular expression aimed at is accomplished, and, as a general rule, we should endeavour to get the necessary force and depth without the use of cross-line, or many different directions of line in shading a figure: but, given any power of draughtsmanship, the individuality of the artist is bound to come in, and it is not likely, nor is it to be desired, that any two artists in line should give exactly the same account of natural fact, or reproduce the images in their minds in the same forms, any more than we should expect two writers to express their ideas in the same terms.