Can you point me to any links or cite any references where I would find more information about this? As I mentioned before, everything I have found thus far wouldn't even fly in a home poker game, much less a casino, because the tools involved would be so obvious to any observer.

And yes, I agree that marking cards is a terrible idea, I'm just trying to determine if this whole 'infrared daub' thing is an urban legend or not. I mentioned it to a friend and he called it BS and now I'm stuck with the burden of proof and unable to find any credible information.