The bonds shall be signed by the president or chairperson and 1 other member of the school board. The school board may adopt a seal to be used in the execution of the bonds. The school board may, in lieu of the signatures required by this section, authorize by special resolution that the signatures of the persons required to sign the bonds may be engraved or facsimiles thereof printed or otherwise transcribed upon the bonds and when such engraved or facsimile signatures shall be so authorized and engraved, printed or otherwise impressed upon said bonds they shall have the same effect as written signatures of such persons. The coupons attached to said bonds shall bear upon their face the engraved or printed signature of the president or chairperson of the school board.