After I posted the previous exercise on this blog I realised that for all the mark makings I had used continuous line marks. This was not my intention, but apparently it just 'happened' as I do a lot of machine quilting. When I worked on the 2nd exercise I paid more attention to differentiation in the type of marks I made.
For this exercise I made 3 different areas of tone (light, medium and dark) using the same marks and the same pencil. Holding the pencil at a low angle and with little pressure creates light tones, putting more pressure on it and raising the angle the darker tones are the result.