If you can buy couple racks of 100, get a few sets of 6 AND ALL THE ERRORS and return the rest. Some of the chips have one word like TUT on one side and something else on the other (like NILE.)

I don't have any of the error chips myself, and I THINK the chips released in June 2001 and later are blank.
Good luck! I'd have to say these are the "Kings" of UV markings... very ccol