Charcoal - getting the darks darker.
I tend to use willow charcoal, but find it difficult to get the darks really dark, even with fixative. I have some compressed charcoal pencils, but like being able to manipulate the values of vine charcoal. I was wondering if anybody has tried nitram fussains
or even the black pan pastels to get deeper darks, or perhaps there's some other means of achieving this?