Irwin Strait-Line has expanded its range of category-leading marking products with the addition of Dust-Off Chalk and Permanent Staining Chalk. Permanent Staining Chalk is great for extreme outdoor conditions because it can withstand harsh weather conditions and months of jobsite wear. In addition to Permanent Staining Chalk there is an existing range of chalk with varying levels of performance, color and special uses. This includes our all new Dust-Off Chalk. So whether working indoors or outdoors, on finished surfaces or in extreme conditions, Irwin Strait-Line has the ideal chalk for every job.