Certain embodiments include a method of manufacturing a polymer sheet having surface relief features. In this method, a layer of pre-polymerized material is provided. A plurality of spatially separated locations on the curable material is exposed to ultraviolet light such that the material locally cures at those locations. The curable material is exposed again such that regions outside those locations are also cured. The curing produces the polymer sheet having the surface relief features; the relief features being at those locations.