Colorado constitution
Article V
Section 29

All stationery, printing, paper, and fuel used in the legislative and other departments of government shall be furnished; and the printing and binding and distributing of the laws, journals, department reports, and other printing and binding; and the repairing and furnishing the halls and rooms used for the meeting of the general assembly and its committees, shall be performed under contract, to be given to the lowest responsible bidder, below such maximum price and under such regulations as may be prescribed by law. No member or officer of any department of the government shall be in any way interested in any such contract; and all such contracts shall be subject to the approval of the governor or his designee.