There are a limited number of positions one can assume when sitting. But it isn’t boring sketching seated people. It is an exercise in proportions. I remember distinctly an instance, many years ago, when the proportions of a drawing on which I was working, became those of the actual model (a picture of a horse). All of a sudden, I felt if my drawing was made real, the horse would have been able to gallop. I try to cross that threshold of with each of my sketches.