Look for instance, at the shadow over the eye or under the nose, which are generally very dark, and compare it with the shadow on the cheek, behind the ear, or under the chin. In the same way decide upon the highest light in the face. Say it is found upon the forehead or on the cheek bone. Be sure that it is the brightest spot in the face, and then compare all the other degrees of light with this.
By studying in this way, and observing the comparative variety of these tones, we arrive at correct values.
This is a most important quality in art and can not be overestimated, for upon a just appreciation of the values in a picture depends its truth. This also serves to illustrate the necessity of making studies directly from nature whenever possible.
CHAPTER VI.
CRAYON PORTRAITS.
Crayon is especially adapted to portraiture, on account of the brilliant effects which it is capable of producing, as well as the great softness and delicacy of finish which may be obtained by its use.
Portraits should, of course, always be taken from life if possible, though if the person be an invalid or is for any other reason unable to give many sittings, a photograph may be used for the beginning. The portrait is carried on from this until well advanced; if one or two sittings from life can then be had in finishing, it will be a great advantage, especially in regard to the expression.
In portraits of children a photograph is frequently a great assistance, particularly if the artist has not had much experience.
In all such cases, however, it is best to decide upon the pose, and sketch it from life, and then have the photograph taken in the pose you have selected.
In this way, the light and shade are arranged to suit the artist, and the pose being decided upon by him, the portrait will have the effect of being drawn from life instead of being merely a copy from a conventional photograph.