What are Liner Socks? A Liner Sock is a lightweight sock that is either made from thin polyester or a lightweight wool material which are breathable to help wick sweat away from your feet. Liner Socks are mainly worn under your thicker hiking socks, and therefore designed to give you that extra layer for protection for your feet; to help prevent blisters. Liner Socks sit close to the skin, and yes you can wear them by themselves for lightweight outdoor activity, but mainly they are recommended to be worn under or over another pair of socks.Designed to be worn for comfort, additional warmth and long distant trail practicality these womens fit Liners with Coolmax will help to keep your feet dry and protected. Worn next to the skin, these liners transport moisture quickly away from the skin out to the main sock where it can evaporate keeping feet dry and comfortable. Extremely quick drying they'll be ready and waiting in the morning after a quick wash. Our engineered womens fit and aFlat Toe Seam minimises bulk that could cause irritation and built on a structure of Lycra, allows our Thermo Fit process to ensure the sock returns to its original shape and size after every wash.