Abstract: A lock-up mechanism for a blanket cylinder in a printing press, the blanket having at each end a straight reinforcing bar formed of metal stock bent into "U" cross section. An arm recessed in the cylinder provides a U-shaped receptacle for receiving the reinforcing bar; the receptacle has first and second supporting surfaces offset from one another for engaging the opposite faces of the bar. A hook is provided on the arm adjacent the second supporting surface for hooking the near edge of the bar, the projection of the hook beyond such supporting surface approximating the thickness of the bar material. The U-shaped receptacle is of such a size as to permit insertion of the bar in a temporarily angled position to clear the hook.