Here's a quick digital portrait experiment that I did earlier today which was loosely based on a black and white photograph of a friend. I started with a rough sketch which I then scanned. Then I inked only what I wanted to remain 100 percent black with a pitt pen. After scanning that, I overlayed it on top of the pencils in Photoshop. The pencils were used as a guide for shading and highlights. Pencil sketch included.