IRWIN's Straight-Line Lumber Crayon is engineered to withstand tough conditions. Its hard wax composition resists smudging, fading, or washing away, even in outdoor or wet environments. The crayon is easy to sharpen, providing a consistent, fine point for detailed work. Ideal for both indoor and outdoor use, the 66401ZR is perfect for creating clear, precise lines that can endure the rigors of construction and woodworking projects, making it an essential tool for any job site.