The present invention relates to thermoplastic structures wherein the inner sealant layer of said structure comprises a polyethylene having a density from about 0. Within the vacuum chamber is a containment region. A light source supplies light to the proximal side of the lens. This optical body can be used, for example, as a reflective polarizer in an optical display. The sulfur dioxide concentration in the steep water of the first steeping tank is greater than the sulfur dioxide concentrations in a plurality of the remainder of the steeping tanks, which maintain sulfur dioxide levels that are substantially equivalent.