With most of my drawings, I start out by sketching in pencil (I have a really kick-ass tecnical pencil I use) and then overlay with ink, much like a comic-book page is drawn. Usually, I then go back and erase all the pencil, leaving just the black and white ink image. However, sometimes I don't get all the pencil - or, more recently, I incorporate the pencil into the final image. There are several spots in this picture where I notice the lighter gray lines of pencil still remain, although I don't think I originally intended them to. You can't see most of them in this scan, though.