I used charcoal to create the look of stucco for the background of this drawing.  It reflects light differently than graphite pencils, so when the two are used adjacent to each other, the graphite areas appear to pop forward.  The combination of charcoal and pencil in used in this artwork helps give the illusion that you could reach out and "grab this bull by the horns".
 

by J. D. Hillberry
Information supplied by: http://www.jdhillberry.com