rulers

Use for hand tools, generally without graduations for measuring and usually flat strips of wood, plastic, or metal, designed primarily as guiding instruments when drawing straight or curved lines; for similar instruments but with graduations designed to aid in measuring or laying out linear dimensions and not designed for ruling against, use "rules (measuring devices)." For usually long bars or strips of wood or metal having straight and true edges and used for a variety of purposes, including cutting or establishing the evenness of surfaces, use "straightedges."