BTL's AquaArmor and Armor pro are made out of entirely UV resistant materials, and can withstand extended exposure to sunlight. Reinforced geomembranes are typically more resistant to UV damage than others, such as PVC. Polyvinyl chloride is particularly sensitive to sunlight, and will quickly become brittle and weaken if exposed to UV radiation.
Liners that are more sensitive to UV radiation are often buried underground in order to protect the material from sunlight.