First, the openings 45 are patterned in {HEAD ~ a mask}, which is {TAIL ~ a bendable plate} 
is
First , the openings 45 are patterned in { HEAD ~ a mask } , which is { TAIL ~ a bendable plate }
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL