I guess it would be bi or triceps. I was watching batman begins the other day, and I noticed that Christian Bale's arms kind of "doubled" like there was a line down the middle. Is this because the biceps and triceps bulk up and have this distinguished line between them? Hehe, I want that! I can kind of see it at the very bottom. Anything you guys can suggest? By the way, if you guys don't know who Christian Bale is, go out and rent Batman Begins right now, hehe. I've pretty much decided that I want his build exactly, except on my body.