The board of county election commissioners shall prepare separate ballots for each of the several political parties for each election precinct in the county. The ballots shall be numbered consecutively and shall set forth the names of the candidates for delegates who have filed affidavits of identity with the county, city, or township clerk under section 624. The ballot shall be prepared in such a manner that the electors of each political party may write, print, or paste the name of a candidate for delegate on the ballot. The delegate ballot at a partisan primary shall consist of 1 sheet of 70-pound white book paper, machine finished or equivalent, with 1 of the political party tickets printed on each side of the ballot. The names on the delegate ballot shall not be rotated. The ballots shall be delivered to the county clerk for distribution to the election precincts at least 10 days before the primary election. However, if there is located within a county, subject to the provisions of this chapter, 1 or more cities or townships, or parts of cities or townships, in which voting machines are used, the board of county election commissioners may, in its discretion, dispense with the preparation of ballots for the election of delegates to the county convention of the several political parties and provide for their election upon the voting machines.