In certain aspects, the invention features articles that have a first layer including a plurality of rows of a first material extending along a first direction, the rows being spaced apart from each other and a center of each adjacent row being separated by a distance less than a wavelength .lamda., and a second layer supported by the first layer, the second layer including a second material. The first layer is configured to transmit about 50% or more of radiation of wavelength .lamda. having a first polarization state incident on the first layer along a path and to specularly reflect about 80% or more of radiation of wavelength .lamda. having a second polarization state incident on the first layer along the path, the first and second polarization states being orthogonal. The second layer is configured so that the article specularly reflects about 10% or less of the radiation of wavelength .lamda. having the second polarization incident on the article along the path, where the path intersects the first and second layers.