Just a tidbit about a "test" that the Lady Luck Casino of Las Vegas did before they converted their equipment over to using magnetic stripes.

Specifically regarding the card shown below, this system uses "light" to read the holes in the card. Therefore the rest of the card must not let light pass through it. Typically, the center of the card (the center layer) will be made with black plastic if there is not heavy printing on the card. This Lady Luck card has what we consider light printing (light coverage of printing). So normally this card always has a black inner core (look at the edge of the card for a black line).

For one batch in 2000 we ran a test with a different type of white plastic that was more opaque (let less light pass through), and it performed well. So one batch of cards was issued without the black inner core (the edge of the card will be completely white). This "variation" only applies to the last issues from Lady Luck, as then they converted to their new cards. All-in-all, about 300,000 were issued with the black core, and 100,000 with the solid white core. This would not apply to earlier version of the Mad Money card, only ones issued from 1999-2001.

Just curious to see if the collector community would consider this a valid variation (my instincts tell me it would, since it is manufacturer-caused).

Scott