Depends on the casino. If they are using it for player tracking also, then all chips must be chipped.

Gene, I still don't understand. It seems to me that the way to track the players is just to get a count at the cage when the winner cashes out. If he loses, all the chips are in the tray. What am I missing here.

They're sure not tracking where the chips are as I have a set of each and am sure many more people have them as well.