The mowing deck on my Ventrac tractor has a lawn "striper" on it. It is just a very long roller (about 50" long) and about 3" in diameter that is attached to the rear of the mower deck and hangs down below the trailing edge of the deck to compress the grass.
I would think you could make one pretty easily if you could find the roller. My mower deck rides in the hydraulic "float" position so it does not really press very hard against the ground while mowing, but the striper really does make a nice wide stripe. On my lawn, which is really comprised of some reclaimed pasture lands, the concept of lawn striping is sort of silly, but I will admit that it looks pretty cool.