Irwin 6490 Strait-Line Permanent Marking Chalk Refill, 8-Ounce, Exterior Use

Irwin 6490 Strait-Line Permanent Marking Chalk Refill, 8-Ounce, Exterior Use

The Irwin Strait-Line Permanent Marking Chalk is an 8-Ounce refill engineered specifically for exterior jobsite use. Available in Blue and Red chalk colors, this permanent formula is designed so lines stay visible after weeks of sun, rain, and continued jobsite wear, making it a dependable choice for tradespeople who need layout lines to hold up outdoors. Packaged in a Yellow/Black finished bottle for quick identification on a busy jobsite, this non-powered chalk refill is built to work with standard chalk reel boxes for fast, accurate line-snapping. Whether marking concrete, wood, or masonry, this permanent chalk formula is engineered to outlast temporary chalk fills in exterior conditions, helping crews avoid the extra time and cost of re-snapping faded lines.

Key Features

• Exterior Use: Formulated specifically for outdoor application where marks must survive sun, rain, and general weather exposure over time.
• Long-Lasting Visibility: Marks remain visible after weeks of weather exposure and continued jobsite wear, reducing the need for re-marking layout lines on extended projects.
• Color Options: Available in Blue and Red chalk colors so crews can match chalk color to jobsite standards or personal preference while retaining the same permanent, exterior-grade formula.
• Marking Type: A chalk formula designed for use in standard chalk line reels and boxes, delivering fast, accurate line-snapping for layout work.
• Container Size: 8-Ounce bottle, sized for convenient refilling of chalk boxes directly on site without frequent reordering.
• Bottle Finish: Yellow/Black bottle coloring for clear, high-contrast identification against tools and materials on a cluttered jobsite.
• Non-Powered Design: A non-energy using product that requires no batteries or power source, keeping operation simple and reliable in the field.

Technical Specifications

• Prop 65 Generic Warning: No
• Country of Origin: CHN
• Prop 65 Warning: No

Typical Applications

• Outdoor Layout and Snapping Chalk Lines
• Jobsite Marking on Concrete, Wood, and Masonry Surfaces
• Construction, Framing, and Renovation Projects
• Exterior Grading and Site Layout Work
• Refilling Standard Chalk Reel Boxes

Why Irwin?

Irwin builds marking tools and accessories intended to hold up to real jobsite conditions, and this Strait-Line Permanent Marking Chalk refill is formulated to keep lines visible through weeks of weather exposure and daily wear. Offered in Blue and Red so crews can match chalk color to jobsite needs without sacrificing the permanent, exterior-grade formula, and packaged in a Yellow/Black bottle for easy identification, this 8-Ounce refill is designed to integrate directly with the chalk reels and boxes professionals already use. As a straightforward, non-powered chalk fill, it gives contractors a reliable option for exterior layout work without the guesswork of chalk that fades, washes out, or loses visibility too quickly in the field, helping crews keep projects on schedule with lines they can trust from start to finish.