The present invention is directed to a modular die unit comprising a plurality of individually shaped plates wherein the shaped plates are stacked in face to face juxtaposition, and when placed into such a juxtaposition exhibit useful polymer forming attributes heretofore unattainable by prior art practices. Single die plates are formed such that the plates exhibit a finite geometric relationship, which in turn provides resistance to flexural deformation of the individually shaped die plates and conversely, improved resistance to variability of the modular die unit and enhanced and predictable formation characteristics of the polymer material formed therewith. Each of said single die plates within the stack forming the modular die unit exhibit an x-direction, a y-direction, and a z-direction, wherein any one of said single die plates exhibit in said x-direction and y-direction to have at least a 50% planar continuity of the total planar continuity.