Abstract: A method of making a solid filter material which filters a predetermined wavelength band from a broader spectrum of radiation includes creating a colloidal structure composed of particles dispersed within a medium, and introducing a solvent thereto. Thereafter, the solvent is evaporated and the remaining structure solidifies into a solid crystalline array. Another embodiment of the method includes electrophoretically attracting the particles in a medium to form an ordered array. The particles can also be fused together by polymerization using one of several methods which are provided. Additionally, one aspect of the invention involves coating the particles with an electrostatically-charged material to facilitate inter-particle interactions.