Charcoal and putty rubber

My local library is my lifeline, I couldn't afford my bibilographic habit, there's no two ways about it, and I get to consult books that maybe aren't excellent but have useful material.  And then there are books that are out of print but are an absolute goldmine, like Learn to Paint and Draw by Hazel Harrison.  I must admit, before this class I would have thought that using an instructional book was 'cheating', if you can't draw you can't draw, but this book takes you through loads of different drawing and painting mediums and techniques.  It's from this book that I picked up the technique of charcoal and putty rubber.  You cover the entire drawing area with a thin background of charcoal, taking time to rub it and get it smooth, and then begin to work with charcoal lines and then lift out highlights with a putty rubber.  Working big makes expressiveness easier