Professor Elemental - Progressions

I've decided to start doing some more musical based drawings for my own amusement more than anything. 
First up is the chap-hop/steampunk legend, Professor Elemental, with his simian butler, Geoffrey appearing in the smoke.

Check out The Prof.'s music and his adventures at his website: www.professorelemental.com

I did this pic in just a couple of hours on a whim on a Sunday afternoon/evening. Much like my picture of Jess and my other of Robert Downey Jr., it's built up using flat layers of grey.