Sisal is a hard natural fiber similar to Manila. Sisal has a lower strength-to-weight ratio when compared to Manila. Sisal can be easily damaged by moisture, ultraviolet (UV) light, and many common chemicals. It is resistant to salt water and is often found in the forms of small twines and cords. Sisal is an excellent option for medium duty use on indoor plants, in the garden, for crafts and for package bundling. Warning: Do not use for overhead lifting, support of human weight or athletic equipment, Do not exceed safe working load detailed on the package. Shock loads (stress, jerk) can reduce working loads by as much as 33%. Never stand in line with ropes under tension; rope (especially nylon) may recoil or snap back. Knots reduce rope strength by 40%. Replace the rope if there are signs of wear, such as broken fibers.