The method 1 further including the step of providing {HEAD ~ a protective, light transmitting coating} on {TAIL ~ the external surface} of said defined envelope 
on
The method 1 further including the step of providing { HEAD ~ a protective , light transmitting coating } on { TAIL ~ the external surface } of said defined envelope
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH