The method 1, wherein {TAIL ~ the inner layer} and {HEAD ~ the outer layer} each defines a thin skin 
The method 1 , wherein { TAIL ~ the inner layer } and { HEAD ~ the outer layer } each defines a thin skin
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH