The invention discloses methods for making photonic bandgap structures and photonic bandgap structures made by those processes. In one embodiment, the photonic bandgap structure is flexible. In another photonic bandgap structure, the structure has a graded, periodic grating. One embodiment of a method according to the present invention comprises the steps of preparing a pre-polymer mixture, positioning that mixture between two slides, exposing the mixture to electromagnetic radiation, curing the mixture, and discarding at least one of the slides. In another embodiment of the method, the pre-polymer mixture is exposed to the electromagnetic radiation through a prism. In one embodiment of the method, the pre-polymer mixture is exposed to the electromagnetic radiation through a lens.In one embodiment of the invention, the photonic bandgap structure is used as a filter in a multispectral imaging device comprising a imaging device, the filter, a processor, and an electronic image storage device.