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.