Minn. Stat. § 204B.30: UNOFFICIAL BALLOTS.

When no official or substitute ballots are ready at the time when voting is scheduled to begin or if the supply is exhausted before the voting ends, the election judges shall contact the municipal clerk and, at the clerk's direction, shall prepare unofficial ballots, printed or written as nearly as practicable in the form of the official ballots, which ballots may be used until official or substitute ballots are available. When unofficial ballots are prepared and used in any precinct, the election judges shall note that fact on the summary statement of the returns for that precinct and specify the number of unofficial ballots that were cast.