It marks through oil, grease, rust, mud, snow - inside or outside. It is absolutely permanent. Solid markers won't fade or wash off like chalk.
The special "stay fresh" twist top keeps paint fresh and ready to use.
Used by divers to mark things underwater. Used on construction sites to label anything exposed to the weather. Used by auto recyclers to mark sheet metal, auto parts, windows. Applications: Steel, Rubber, Cloth, Plastic, Cardboard, Wood, Glass, Concrete, Stencil Craft projects.