Here is are few shots of a card I am testing just to try out some more wow effects. Here above you see 2 card with nothing on it, one is white and other chrome. See below what happens when you hold them against the light.
And the left one you see the text light up and the right one the chrome becomes transparent. The chrome one actually works better and does not need a very strong light to make it possible to read it. Also the chrome one also works when you put it over your the screen of your phone, when the back light is on with a white screen.
This is just a test and not be producing this but will test some things more and see what kind of possibilities there are. Really got allot of the chrome foil left and will do some cool designs with it.