An edge coating of polymer or {HEAD ~ other material} is disposed on and seals {TAIL ~ the interior edge} of the base sheet and may project beyond the facial planes of the base sheet to define protruding rims extending around the aperture 
An edge coating of polymer or { HEAD ~ other material } is disposed on and seals { TAIL ~ the interior edge } of the base sheet and may project beyond the facial planes of the base sheet to define protruding rims extending around the aperture
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL 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