US Patent 7309518 Radial tilt reduced media

A storage media can comprise: a plastic substrate, an optical layer, a reflective layer disposed between the optical layer and the substrate, and an adhesive layer disposed between the optical layer and the reflective layer. The optical layer can have an optical layer composition different from the substrate composition. The storage media has a radial deviation over time of less than or equal to 1.15 degrees at a radius of 55 mm, when exposed to a cycle at 25° C. of 50% relative humidity—90% relative humidity—50% relative humidity.