Markal Valve Action Markers are manufactured with a fast-drying liquid paint for long-lasting mark identification on a variety of surfaces. With a marking range of -50°F to 150°F, Markal Paint Pens feature a Dura-Nib medium bullet tip that resists wear, as well as a durable metal barrel to reduce breakage. Safe for use on rubber, glass, plastic, steel, iron, cloth, pipes, and textiles.