It was particularly interesting how the addition of chalk enables you to think more easily in terms of the flow of light. With just charcoal and the white of the paper you have to achieve the lights negatively (by omitting to put down charcoal) but with a stick of chalk in hand you can actually identify the areas receiving the most light and simply draw it in over the grey of the paper. The result is a really pleasing sense of depth and form.
That said, it was initially difficult to resist putting chalk all over the place. In this figure there was a marked fall-off of light as the lower parts of the figure receded from the light source. Eventually, after some push and pull, I achieved a gradation of light which really adds atmosphere and gives a nice sense of the figure existing in space.
*Those in the vicinity of Bristol can see some of my other figure drawing at the Royal West of England Academy 164th Annual Open Exhibition in Bristol which runs from 9th October to 27th November.