. "rst reflectivity at a first viewing angle and a second reflectivity at a second viewing angle, the first reflectivity and the second reflectivity being expressed as a percentage of total reflectivity, wherein the first reflectivity is less than the second reflectivity by at least 20%, wherein the plurality of thin-film layers are arranged as (aH bL)n aH wherein n is an integer and a and b are mult" . . . .