Light Thermal Base Layer Knit Fabric 180GSM Lyocell Wool Blend 170cm Wide Smooth Face Fabric for Base Layer Tops Base layers fail in two ways: they trap moisture, or they bulk up under a shirt. At 180gsm this knit stays thin enough to disappear under a woven top, while the wool fraction buffers humidity as body temperature moves through the day. The smooth lyocell face reduces the friction that makes wool-blend base layers feel prickly at the neck and cuffs — the complaint