Our lightest weight base layer fabric is quick drying, fast wicking, breathable and comfortable. Styles made from this 4-season base layer material will help regulate body temperature during high exertion activities throughout the entire year. With an impressive warmth-to-weight ratio, our SILKweight products can be worn alone or under our TEMPOweight, CONTOURweight or EXPEDITIONweight products.