Research has shown that polyester, although lighter than cotton will absorb the odor of the perspiration and not release it when washed. Hence you may find yourself putting on a newly washed polyester shirt which still contains your body odor from a previous round of golf.
Cotton on the other hand, as a natural fiber will allow the perspiration to wash right out, leaving you a clean fresh smelling golf shirt after each wash to play in.
I guess the pros could always change into a new polyester golf shirt after each hole. And at the same tine increase the viewing figures for both womens and mens golf. ----------------------------------------