The yarn used to knit these socks was spun with alpaca fibre, wool and nylon. Alpaca fibre is finer and denser then wool, so more fibre is compacted into a fine yarn, resulting in a lighter feeling but warmer fabric then one made with wool alone. Wool has a resilience that alpaca lacks, helping garments made with wool to spring back into their original size and shape after washing. Nylon gives its strength to this exceptional blend. The fine ribbed fabric traps air keeping your feet warm, dry and comfortable. Best of all they are thin enough to slip into most shoes so you can easily enjoy them all winter long. Feel the difference that alpaca makes!