The drape comprises {HEAD ~ a pair} of {TAIL ~ stacks} of panels which are folded around parallel fold lines 
of
The drape comprises { HEAD ~ a pair } of { TAIL ~ stacks } of panels which are folded around parallel fold lines
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH