Engineered for professionals who demand precision and durability, the Irwin® Strait-Line® 2032160 5 lb Black Permanent Marking Chalk delivers bold, long-lasting lines that stand up to the toughest jobsite conditions. Whether you're working indoors or outdoors, this high-performance chalk ensures your markings remain visible and reliable for weeks—even in harsh weather.

Key Features:

• Permanent, Weather-Resistant Formula
  Designed to resist fading, smudging, and wear, this chalk creates high-contrast black lines that remain visible after exposure to rain, sun, and foot traffic. Ideal for long-term projects or high-traffic areas.

• Hi-Flow Nozzle Cap
  The innovative Hi-Flow nozzle allows for quicker fills and smoother chalk flow, reducing clumping and mess. This feature is especially useful when working with high-density permanent chalks.

• Flip-Top Airtight Cap
  Keeps moisture out and chalk dry, preserving the integrity of the chalk and preventing clumping during storage and use.

• Versatile Surface Compatibility
  Works effectively on a wide range of surfaces including:

  • Wood
  • Drywall
  • Concrete
  • Stone
  • Metal

• Bold Black Color for Maximum Visibility
  The proprietary formulation includes calcium carbonate, black iron oxide, and silica-crystalline quartz, producing sharp, dark lines that are easy to see and hard to miss.

• Professional-Grade Packaging
  Comes in a 5-pound plastic squeeze bottle with a fast-fill spout, making it easy to refill chalk reels quickly and efficiently.

Specifications:

• Model: 2032160
• Color: Jet Black
• Weight: 5 lb (chalk is measured by weight, not volume)
• Type: Permanent marking chalk
• UPC: 024721021229
• Brand: Irwin® Strait-Line®

Ideal Applications:

• Construction layout and framing
• Masonry and concrete marking
• Carpentry and woodworking
• Roofing and siding alignment
• Industrial and commercial job sites