From Cybersecurity & Infrastructure Security Agency website (CISA):
Committing fraud through photocopied or home-printed ballots would be highly difficult to do successfully. While the specific measures vary, in accordance with state and local election laws and practices, such security measures include signature matching, information checks, barcodes, watermarks, and precise paper weights.
Ballots are similar to paper money in that there are precise tints, formats and paper that they use that would be hard to duplicate. But... if you have corrupt people, unobserved by the opposition party, pushing though fake ballots, it doesn't matter if the ballots are compliant.
We'll see if some of those ballots spontaneously combust or get damaged by burst water pipes before they can be closely inspected.
![Roll Eyes (Sarcastic)](https://pics3.city-data.com/forum/images/smilies/rolleyes.gif)