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