The material of the inner liner is folded over at {HEAD ~ opposite edges} to form increased thickness margins at {TAIL ~ opposite ends} of the pack 
The material of the inner liner is folded over at { HEAD ~ opposite edges } to form increased thickness margins at { TAIL ~ opposite ends } of the pack
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH