Quality materials and tailoring. So midweight materials probably aren't used in the summer here in Florida, but are definitely being used now.
Men'S Long Sleeve Polo Shirt - Slim Fit, Stretchy, Breathable Collar
43 Review
Gildan Performance Men's π Clothing and Shirts with Moisture-Wicking Polyester
44 Review
Van Heusen Traveler Stretch Men's Shirt
47 Review
INFLATION Bamboo Shirts Sleeve Elastic Men's Clothing in Shirts
45 Review