The drawing at this point is progressing nicely, but I find that I am not able to get the tonal values as dark with the carpenter’s pencil as I’d like. So, I introduce a 4B graphite pencil to push the blacks and make the space even deeper in the shadow areas. I also decide I’d like a very dark space around the figure, and I know to achieve this, I’m going to have use a dark graphite block for shading the final stages.
If you're not sure about which pencil or block to use, check out this article on graphite pencils and drawing materials. You don't have to use the exact same things - a 3b or 6b will do if you have one; and a woodless pencil is a good alternative to a graphite block for covering areas.