I also love the old style look of minimal line with judicious use of washes.
As with many cartoonists Mark didn't set out to make a living from cartoons - hear all about his cartooning journey over at his interview with Tom Racine on Tall Tale Radio. He's not just funny on paper! (We have another thing in common - a love of Legos - between us we probably have an entire house full of Legos!)
And go subscribe to him on Gocomics so you can read his work every day!!