Mike Sobey is one of best commercial illustrators in the city of Chicago. I have learned a great deal in the past decade that I've worked with him at Steve Edsey & Sons. Mike's work consists mostly of advertising art, although he did illustrate some covers for Rick Lundeen's self published graphic novels.
Mike has a number of distinct styles. The one in which I learned how to marker comps and paint from is his realistic tone-on-tone storyboards:
He also does event sites:
And a style called "loose line":
He employs, in his black and white work the "60/40 rule" What this means is that in order to have good balance in b/w, artwork has to be either 60% black & 40% white or vice versa. I try to keep this in mind when working on the b/w Femforce art: