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