Overview Reviews Product Description This Irwin strait-line permanent marking chalk is designed for exterior use.The marks are visible after weeks of weather exposure and jobsite wear. Irwin Tools Catalog Product Videos Custom Field Manufacturing country CN Product Reviews Write a Review Write a Review × Irwin Strait-Line® Black Permanent Marking Chalk 5lbs 2032160 Rating * Select Rating 1 star (worst) 2 stars 3 stars (average) 4 stars 5 stars (best) Name Review Subject * Comments *