The _modus operandi_ is as follows: Place the drawing over a piece
of mounted canvas of the desired coarseness of grain, and, holding
it firmly, rub a lithographic crayon vigorously over the surface
of the paper. The grain of the canvas will be found to be clearly
reproduced, and, as the crayon is absolutely black, the effect is
capable of reproduction by the ordinary photographic processes.

CHAPTER IV

VALUES

[Side note: _The Color Scheme_]

After the subject has been mapped out in pencil, and before beginning
the pen work, we have to consider and determine the proper disposition
of the Color. By "color" is meant, in this connection, the gamut of
values from black to white, as indicated in Fig. 23. The success
or failure of the drawing will largely depend upon the disposition
of these elements, the quality of the technique being a matter
of secondary concern. Beauty of line and texture will not redeem
a drawing in which the values are badly disposed, for upon them
we depend for the effect of unity, or the pictorial quality. If
the values are scattered or patchy the drawing will not focus to
any central point of interest, and there will be no unity in the
result.

[Illustration: FIG. 23 C. D. M.]

There are certain general laws by which color may be pleasingly
disposed, but it must be borne in mind that it ought to be disposed
naturally as well. By a "natural" scheme of color, I mean one which
is consistent with a natural effect of light and shade. Now the
gradation from black to white, for example, is a pleasing scheme,
as may be observed in Fig. 24, yet the effect is unnatural, since
the sky is black. In a purely decorative illustration like this,
however, such logic need not be considered.

[Illustration: FIG. 24 D. A. GREGG]

[Side note: _Principality in the Color-Scheme_]

Since, as I said before, color is the factor which makes for the
unity of the result, the first principle to be regarded in its
arrangement is that of Principality,--there must be some dominant
note in the rendering. There should not, for instance, be two principal
dark spots of equal value in the same drawing, nor two equally
prominent areas of white. The Vierge drawing, Fig. 25, and that
by Mr. Pennell, Fig. 5, are no exceptions to this rule; the black
figure of the old man counting as one note in the former, as do
the dark arches of the bridge in the latter. The work of both these
artists is eminently worthy of study for