Described is a method of forming a structure having viscoelastic properties. The method can include a) depositing a layer of droplets of a solidifying material and a non-solidifying material, the droplets being deposited according to an occupancy matrix specifying voxels for the solidifying and non-solidifying materials, the solidifying and non-solidifying material being interspersed within the occupancy matrix, the occupancy matrix being generated by a probabilistic function; b) exposing the droplets of solidifying material to ultraviolet radiation to cure the solidifying material; and c) repeating a) and b) to deposit additional layers of droplets of solidifying and non-solidifying materials, thereby forming the structure having viscoelastic properties.