The members of the commission shall not receive any pay for their services under the provisions of this chapter, but the general assembly shall from time to time appropriate any sums that may be necessary for clerical assistance and other actual expenses incurred by the members of the commission in the performance of their duties. All printing required by the commission, including the printing of its reports to the general assembly, shall be paid out of the appropriation for state printing upon vouchers approved by the chairperson of the commission and the state purchasing agent.