These industrial marker pens have all the toughness and reputation that you come to expect from International Plastics. They are perfect for Hard to mark surfaces. They dry fast, are opaque, they can stand up to weather and are fade resistant. These Permanent Markers are long lasting and won't dry out, even when stored on a shelf for years without being used. These markers won't fade in weather conditions. Try an Industrial Permanent Marker today and see for yourself. Markers are pre-packaged in cartons of a single color. Colors cannot be mixed within a carton.