This is something that I have been working on for the last four hours (it's 2AM at the moment).
This style of image traces back to my original style, before I ever even dared to play with colour. Back in high school, I used to do a lot of things like this. I did not go so well in my year 10 mathematics class, because I spent more time drawing than listening to my teacher. Her teaching skills were bollocks anyway, so what do you do?
On the left arm (his right), you might notice a small blotch around the wrist. That's actually part of a blueberry muffin; I couldn't get it off!
This image was illustrated using a standard 0.5mm mechanical pencil.