okay, okay, chrome is not clear en masse, but the chrome that you see on parts like this frame is measured in millionths of an inch - even hard chrome is still measured in this range. The chrome gives the nickel plate (which is normally slightly yellow, and subject to tarnishing) a bluish cast, so it doesn't go on completely clear. It is very, very hard, but the "Chrome" look that you see is actually very highly polished nickel. Chrome can go over other surfaces too, producing, among other things, black chrome like my Husky sockets, or flat chrome like you'll find in some military applications.