This lightening of shadows in the middle by reflected light and darkening towards their edges is a very important thing to remember, the heavy, smoky look students’ early work is so prone to, being almost entirely due to their neglect through ignorance of this principle.  Nothing is more awful than shadows darker in the middle and gradually lighter towards their edges.  Of course, where there is a deep hollow in the shadow parts, as at the armpit and the fold at the navel in the drawing on page 90 [Transcribers Note:  Plate XVIII], you will get a darker tone.  But this does not contradict the principle that generally shadows are lighter in the middle and darker towards the edges.  Note the luminous quality the observation of this principle gives the shadow on the body of our demonstration drawing.

This is a crude statement of the general principles of light and shade on a simple round object.  In one with complex surfaces the varieties of light and shade are infinite.  But the same principles hold good.  The surfaces turned more to the source of light receive the greatest amount, and are the lightest.  And from these parts the amount of light lessens through what are called the half tones as the surface turns more away, until a point is reached where no more direct light is received, and the shadows begin.  And in the shadows the same law applies:  those surfaces turned most towards the source of reflected light will receive the most, and the amount received will gradually lessen as the surface turns away, until at the point immediately before where the half tones begin the amount of reflected light will be very little, and in consequence the darkest part of the shadows may be looked for.  There may, of course, be other sources of direct light on the shadow side that will entirely alter and complicate the effect.  Or one may draw in a wide, diffused light, such as is found in the open air on a grey day; in which case there will be little or no shadow, the modelling depending entirely on degrees of light and half tone.

In studying the principles of simple light and shade it is advisable to draw from objects of one local colour, such as white casts.  In parti-coloured objects the problem is complicated by the different tones of the local colour.  In line drawing it is as well to take as little notice as possible of these variations which disturb the contemplation of pure form and do not belong to the particular province of form expression with which drawing is concerned.

Although one has selected a strong half light and half shade effect to illustrate the general principles of light and shade, it is not advisable in making line drawings to select such a position.  A point of view with a fairly wide light at your back is the best.  In this position little shadow will be seen, most of the forms being expressed by the play of light and half tone.  The contours, as they are turned away from the light, will naturally be