Having established an outline of the structure and light, I merely have to consult the original sketch to to give a fuller definition to the shadows.
I begin shading at the figure's left arm and move outward across the torso. I do not yet bring out the darkest darks, because I may need to make erasures later.
Below, I continue shading outwards from the center. I have established by now all the basic muscular and skeletal forms to be fleshed out. I try to do this with a fluent hatching stroke to avoid making prominent lines in the interior of the figure. Besides giving a convincing roundness to the form, it also puts an added emphasis on the harshness of such lines that I do want to feature, such as those in the deltoid and triceps. This allows me to stress angularity without sacrificing realism.
If you click on any of the images for a close up view, you will see that my hatching is done in largely uniform direction. This is a choice that grew out of starting shading on the figure's left arm. This stroke was a natural choice in this regard, and I found that by continuing it across the figure, I could produce a rhythm, of which the sharp lines of the arm are a kind of climax. The only cross-hatching is in the torso, where it is fine enough to be imperceptible.
I began this project with a sketch from a live model. This was done quickly and roughly, as a mere practice exercise. My goal was basically naturalistic—to record the body of the model in the pose that he had chosen.
However, I emphasized certain elements that I found striking. The angularity of the shadows produced by multiple lights sources; the separation of the muscles into rotund masses; the elongation of the limbs; these were all spontaneous stylizations suggested by the model's body. These were what made me want to develop the sketch further
The first step was to identify what I liked about the drawing and the pose, and to distinguish these from what was accidental and irrelevant.
I did this by laying tracing paper over the original sketch and manipulating various aspects of the figure to see which elements were essential and which could be changed. I found that I liked the twist of the body and that this could be emphasized by adjustments of the background limbs, without much change to the position of the torso or the front arm and leg.
You can see the changes on the tracing paper above. The torso and arm have been slimmed down, and the fold of his right shoulder blade projects out to suggest a view of his back and to make the backward projection of his arm more convincing.
Note the ghost of the original position of the leg. It was difficult to decide between the two poses. The new position was the better choice, I think. It stresses the "artificial" nature of the pose, that is, the body now asserts itself by stressing the fact that it is on display.
Next, I transferred the new design to drawing paper with a light outline using a black pencil. I lightly blocked in the shadowed areas.