The 65102 Strait-Line 5lb Red Chalk is what you need to help get things Strait. The Strait-Line chalk is great for outdoor use, carpentry, bricklaying, masonary, roofing,carpet installation,floor and wall tiling, painting, decorating and many other uses. Red chalk is what you would need for a permanent line that will be able to endure the elements of the environment. For more than 30 years, Strait-Line products have represented the standard for excellence and performance in marking tools.