In {TAIL ~ several embodiments} {HEAD ~ different areas} of the film have different thicknesses for producing different interference colors 
In { TAIL ~ several embodiments } { HEAD ~ different areas } of the film have different thicknesses for producing different interference colors
REL TAIL TAIL TAIL TAIL TAIL TAIL HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH