Irwin STRAIT-LINE permanent staining chalk is formulated for exterior applications where lines need to withstand the elements. Unlike standard marking chalk, this permanent formula creates staining marks that will not wash off, making it ideal for outdoor construction layout, roofing, and site marking. The crimson red color provides high visibility against most surfaces.

• Permanent/staining formula - marks will not wash off
• Designed for exterior applications
• Crimson red color for high visibility
• 6 oz bottle
• Works with all standard chalk line reels
• Fine powder for clean, crisp lines

Note: Permanent chalk creates staining marks. Use standard chalk for interior or temporary marking applications.