Filson’s lightweight shirts for warm-weather action are made from a variety of fabrics. Whether the construction is knitted or woven, 100% cotton or a moisture-wicking technical blend, each one is designed for comfort in the heat. Our tried-and-true Feather Cloth shirts have been a staple since the 1990s. Our Twin Lakes Sports Shirts have been updated with a polyester and cotton blend with a bit of Lycra for flex. This remarkable fabric provides the comfort of cotton with the exceptional temperature regulating and wicking ability of COOLMAX® polyester fibers.