Basically any cards that are plastic coated and novelty cards.
Plastic cards are the flourishers Anti-Christ. They are the evil children of the Devil, and should be avoided at all costs.
Plastic cards should come with a warning on the side of them from the Surgeon General like cigarettes do.
WARNING: Plastic cards have been known to cause horrible fans, bad springs, no creativity, loss of memory, loss of feeling in extremities, spontaneous thumb lock, gangrene, erectile dysfunction, spontaneous combustion, depression, heart palpitations, liver failure, explosive diarrhea, comas, blindness in the left eye, the clap, the drip, bleeding ulcers, brain tumors, deafness in the right ear, embarrassing underwear skidmarks, and even death.
For the love of God, use them at your own risk.
heh I think they were talking about the cheap, clear plastic cards you find at Mcdonalds or Walmart...the supposedly "waterproof" kind of cards