How to shade a head, one light at a time

Shading goes wrong most often when the light isn't decided. A bit of shadow goes under the nose because noses have shadows, some more goes down the cheek because cheeks do, and the head ends up lit from three directions at once. Choose one light first, and every shadow on the head follows from that one choice.

The figures here come from our head lighting reference: the same hard-plane head at a 45-degree turn, lit from eight directions. Because only the light changes from frame to frame, you can see which shadows move and which stay. The head turns toward the right of the page, so its ear side is on the left and its face side on the right; "far" means the side turned away from you.

Four things to look for

• The lit side: every surface turned toward the light.
• The shadow edge: the line where the form turns away from the light. It falls on a turn of the form, so it follows the planes of the head.
• The form shadow: everything on the far side of that edge.
• Cast shadows: shadows thrown by one part onto another, like the nose onto the upper lip or the jaw onto the neck. They have sharper edges than the form shadow, and their shape depends on the shape of the surface they land on.

Shade in four passes

1. Mark where the light comes from. A small arrow in the margin is enough, with a note of whether it comes from above or below, since that decides whether the nose shadow lands on the lip. Every later decision gets checked against it.
2. Draw the shadow edge. A plane facing the light is lit, and a plane turned edge-on to it is where the edge goes. On most lights that means the side of the brow, the cheekbone, the side of the nose and the jaw. Draw one thin, light line along them.
3. Fill the shadow side with one flat tone, without varying it yet. If the head reads as lit from one direction at this stage, the rest is refinement.
4. Add the cast shadows, then the darkest accents where two surfaces meet, such as the corner of the eye or the line between the lips. Where a cast shadow falls inside the form shadow it merges with it, so draw only the part that lands on the lit side.

Only after these four passes do you blend the edge, add the halftones on the lit side, or lift any light back out of the shadow.

One light at a time

Light from the front. Most of the head is lit, so the shadows are small. Most of them sit under something: under the brow, under the nose, under the lower lip, under the jaw onto the neck. A thin form shadow runs along the back edge of the skull behind the ear, where the head turns away from the light. With a front light these few shapes carry the form, so keep them small and clear, and don't add shading where no form turns away and nothing casts it.

Light raking across the face. Now most of the head is in shadow and the light picks out a few planes. Most edges of those lit shapes are the shadow edge and show where a plane turns; a few, like the brow's shadow over the eye, are cast shadows. This is the most useful light to study, because it draws the planes for you.

Light from the ear side. The side plane and the ear are lit, and the front of the face stays mostly lit too. The shadow edge has moved to the far temple, the far side of the nose and the far cheek. Compare this with the raking frame above, where the side of the head was in shadow and only the front planes caught the light: the light has crossed to the other side of the head, and the shadow edge has moved with it to a different set of turns.

Light from behind. Almost everything you can see is form shadow. The outside shape of the skull and jaw does most of the work, so check the silhouette before anything inside it. Keep the shadow as one connected tone and let a few small lights describe the features.

A short exercise

Pick three frames from the head lighting reference: one front light, one side light and one from behind. Draw the same head three times, using only the four passes above and no blending. Then lay the three drawings side by side. In each drawing, every shadow edge should sit where the surface turns away from your arrow. If one crosses a surface that faces the light, check whether something casts that shadow; if nothing does, it doesn't belong there.

All eight frames, with notes on where each light lands, are in the free head lighting reference. The full set is the head lighting reference, volume 1.

This guide is one step in how to draw the head at any angle, which puts all the head guides in order.