Fabrication of homogeneous, flexible, polymeric, dielectric Bragg gratings is demonstrated. The Bragg grating is assembled on a poly(ethylene terephthalate) film using polymeric colloidal microspheres of polystyrene (PS) and poly(methyl methacrylate) (PMMA) (see Figure). The microspheres are stacked successively with precise control at the nanometer scale and the gratings, free of metal and inorganic materials, cover a relatively large area.