Abstract: Variable index light extraction layers that contain a first region with a first material and a second region including a second material are described, where the first region has a lower effective index of refraction than the second region. Optical films and stacks may use the variable index light extraction layers in front lit or back lit display devices and luminaires.

Abstract: A method of forming an article is provided. The method can include providing a substrate comprising a surface. The method can further include forming a solvent soluble layer on or over the surface of the substrate in a pattern, the pattern defining one or more first portions of the surface that are overlaid by the solvent soluble layer, and one or more second portions of the surface that are free of the solvent soluble layer. The method can further include forming a second layer on or over at least one of the first portions and at least one of the second portions, wherein the step of forming the second layer includes buffing an exfoliatable material on or over at least one of the first portions and at least one of the second portions. The method can further include removing the solvent soluble layer by applying a solvent to the substrate.