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 - great for inside or outside use. Just twist the end to advance the paint when you are ready to use more. The tip offers a broad stroke and can be trimmed with knife for smaller marks. Ideal for use on wood cloth canvas plastic steel iron rubber cardboard glass fiberglass and concrete. Alcohol based cleaners will remove the ink from non-porous surfaces.