If you hold up your AMEX Green to a backlight, the squiggle mark allows a green light to shine through the card.
Much more cool than any all-metal card 
The squiggle says "Member Since" on the front, and "Reclaimed" on the back.
So many cards have such cool features under a black light. I'm a photographer and have thought about trying to get some high quality long exposure macro shots of neat features of cards under the black light. Maybe something to try if my office finally decides to shut down and I have some extra time on my hands.
