In between thunder storms I sketched some trees at the back of our house. Not actually black..but nearly. I used Derwent water soluble sketching pencils and graphitone 2b pencil. Quite similar results, but I think the graphitone has the edge for me.
The best bit is wetting the drawing and seeing it transform . The graphitone can be dipped in water to add extra texture, I'm not sure that would do the wood much good on the sketching pencils.
I will definately be buying some more graphitone pencils, no problem about leads breaking either!