Teak
Teak is naturally water-resistant and physically very strong and durable. It is not prone to significant expansion or contraction with humidity changes. The oils in teak are what make it weather-resistant and it requires basically no care when left outside.
Synthetic Rope
Synthetic rope materials commonly used include polypropylene, nylon, and polyester. All of these are plastic-based material. Synthetic rope can be made of just one or a combination of these materials.
