Our HDPE liner is made of industrial strength, virgin high density polyethylene. This extremely durable liner is constructed of 3 HDPE layers (one white and two black) that are fused together to form a total thickness of 20 mil. It is suitable for both indoor and outdoor applications due its superior UV resistance. It can be used with either the white side or the black side exposed, offering additional design flexibility, based on design preferences. Fish safe and suitable for potable water storage. Unlike liners made of other materials, HDPE liners have been approved by US based organic certifying organizations like Oregon Tilth and others. We provide our HDPE liner in a wide variety of lengths and widths to suit your needs.