Well, you see them done on case windows with an etch print that makes it look like the window is etched.
I wasn't sure If that was the case or if it was a certain color.
I have an 8.5x11 nvidia logo in green on the side of my rig.
No pics of that atm, but I got that and 4 other circular logo's about 6" diameter for 12 bucks shipped.