For example, if thinner face coatings are desired, then spacers 208 and 211 can be relatively thinner whereas {HEAD ~ relatively thicker spacers} result in {TAIL ~ relatively thicker face coatings} 
result in
For example , if thinner face coatings are desired , then spacers 208 and 211 can be relatively thinner whereas { HEAD ~ relatively thicker spacers } result in { TAIL ~ relatively thicker face coatings }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL