The perfect shirt for everything, every day. Royal Robbins added breathable cotton comfort to their sustainable, machine washable OysterYarn™ polyester to create a plain weave plaid that provides light warmth, breathability, and resists odors, wrinkles, and static. This shirt easily goes from weekday to weekend and looks good doing it. Cotton and OysterYarn™ blend in a comfortable, versatile plain weave plaid.