DEMONSTRATION
From the start of this oil sketch, all marks are made with a brush, a fine rigger and dilute paint. If you do need to make a small drawing in preparation to understand the shapes, weight, angles and proportions of the head beforehand, do this in a sketchbook rather than use pencil or charcoal on the painting surface. After the initial drawing, the paint is applied a little more thickly with an opaque covering, as it is intended to be a quick tonal study rather than to be built up over a more sustained period.
The surface I used for this small oil sketch was oil-primed linen, which I use frequently. The linen has a fine grain and the oil primer provides a smoother surface to work on; also it isn’t as absorbent as surfaces prepared with gesso primers.
As the position of the head is established on the canvas, a small amount of the mid-tone mix is used with a brush. The paint is diluted with a small amount of Sansodor so that the consistency is similar to that of an ink wash. It is with this diluted paint that the initial marks are made.