Nylon (polyamide) cords are a strong, abrasion resistant and durable. Nylon cords with core-mantel structure have really high breaking strengths. Nylon cords have few percentages of stretch. Nylon fiber absorbs some water, and thus cord length varies a little according to humidity. The fiber also loses some of its strength in very dry conditions of extremely low and high temperatures. Nylon fiber is slightly sensitive to UV radiation, but usually sunlight doesn't cause significant damage to protected core-mantel cords.
Polyester is a weather resistant and durable choice for cords. Polyester fiber doesn't absorb much water and the cord length is not affected by moisture. Polyester stands well against UV radiation aka sunlight, black color is the best option in this regard.
Dyneema (Spectra, polyethylene) is an extra strong cord with minimal stretch. In many cases, the cord contains a Dyneema core and the surrounding sheath is made of polyester or nylon fibers. Dyneema fiber is slightly sensitive to UV radiation but when protected and especially when sheathed with polyester, they stand well against sunlight. Dyneema cords are rather expensive, but when minimal stretch combined with great strength is needed, then Dyneema is the choice.
