Unitary filters for airbags. The filters may be formed from various combinations of ceramic grit, ceramic fiber, metal grit, metal fiber, and non-metal fibers. Combinations of disparate particle sizes may be used to increase filter diffusion and reduce the size of particles filtered. The disparate size particles may be uniformly mixed, or may be in relatively discrete layers. Fibers may be used to increase the strength of the filter. The fibers may be mixed with an initial slurry, or the slurry may be pressed into a mat of the fibers.