Lot codes were only tracked for paper that was OK for food contact or FSC certified. Your run of the mill stock wasn't tracked that way.

But yea, I would hope paper ballots would require a special blend of paper, kind of like how money is printed, so that there are security measures in the paper itself that make it extremely hard to reproduce, and that the paper itself would have a chain-of-custody so that some cheap Chinese or Mexican knock-off would be easy to identify. But again, this would require physical access to the ballots, which is what these politicians are preventing.