Since anyone can print their cards on whatever material, how do you ensure the integrity of the game? Not a big deal obviously in casual play, but if the game sees Comp REL, it seems vulnerable given the fact that you're relying on players to efficiently produce a consistent deck (materials-wise). After all, there's a reason why judges often inspect MTG alters before allowing them to play them in the deck.
@shawnstoppable Just like in any other game, if there is inconsistency, then you will be called out for it. At higher level RELs there would definitely be deck checks, just as there are in any other major game. Judges would be looking both for legal deck lists and card ownership as well as anything that may be "marking" cards.