A tough marker for tough jobs, the Solid Marker is solidified paint in a marker stick. It marks through oil, grease, rust, mud, snow and more, and is great for inside or outside use. The paint dries within minutes, and is permanent once dry. The special twist mechanism that advances the paint keeps it fresh and ready to use. The tip offers a broad stroke and can be trimmed with knife for smaller marks. The original Solid Marker has a 13mm tip and the Slim Solid Marker has a 10mm tip. Ideal for use on wood, cloth, canvas, plastic, steel, iron, rubber, cardboard, glass, fiberglass and concrete. Alcohol based cleaners will remove ink from non-porous surfaces. Meets ASTM and ACMI non-toxicity standards and is AP seal certified.