stacking the plurality of base sheets together with their interior edges aligned with each other, the aligned edges defining and being exposed on {HEAD ~ the walls} of {TAIL ~ a cavity} 
of
stacking the plurality of base sheets together with their interior edges aligned with each other , the aligned edges defining and being exposed on { HEAD ~ the walls } of { TAIL ~ a cavity }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL