A wood based material may be formed having a permeability which is {HEAD ~ at least 5 times that} of {TAIL ~ the untreated wood} 
of
A wood based material may be formed having a permeability which is { HEAD ~ at least 5 times that } of { TAIL ~ the untreated wood }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL