Irwin Strait-Line Permanent Staining Marking Chalk in Midnight Black provides bold, weather-resistant lines that won't wash away. Designed for use with chalk line reels, this permanent formula is ideal for outdoor construction and roofing applications where lasting marks are needed.

• Permanent staining formula - marks will not wash away
• Midnight Black color for high visibility on most surfaces
• 6 oz bottle with easy-pour design
• For use with standard chalk line reels
• Ideal for exterior and roofing applications

Note: This is permanent staining chalk - not recommended for interior or finish work where chalk marks need to be removed.