My favorite medium is pen. When I sketch with pencil I tend to erase and nit-picked and tweak constantly. A professor of mine noticed and mentioned how much it slowed me down and made my lines too stiff and unnatural, and he gave me an assignment: sketch 3-4 times a day, everyday for one week, and only use pen. I immediately noticed a difference in not only the speed of my sketches, but also the style and quality. I enjoyed the assignment so much that even now almost all of my sketches are in pen. I also went a step further and created a penned portrait series of 4 as my final work from that class. Here’s one of them
The original is about 3ft x 4ft and is based on photography by Andres Serrano. (Careful browsing through his work, he can be graphic/disturbing. Definitely NSFW) The entire piece, sketch to finish, was done with .005 micron pens. The texture and gradient was created with light squiggly patterns layered and layered… and layered and layered. The whole thing took me about 32 hours beginning to end.