This Marshalltown Masons Line is made from twisted nylon that has been heat set after winding to increase stability. Not affected by mortar, oil or mildew and will not absorb water. Suitable for staking out sites, concrete and landscaping layout and brick/block laying. Made in the U.S.A1 x Marshalltown M632 Masons Line 76.2m (250ft) - Fluorescent Yellow