I always love working over sketches or commissions because there's more of a rawness and/or fearlessness to that work. We as artists tend to experiment or let loose with them, including Jim--though his sketches tend to be waaaay better than most people's panel work. I use opportunities like these to try new style's or approaches to his art and this was no exception.
Last sketch we did was mostly cool tones so I thought I would do an orange moon and sky for extra drama and to pop him. I loved the Dark Knight film and that helped fuel my inspiration for this piece.
Wouldn't it be cool to see a Jim Lee DK Joker? Cough-hint-hint-cough!!