The key to staying comfortable on cold days is staying dry. The Pearl Izumi Women&';s Merino Longlseeve Baselayer uses a construction method called plating to place recycled polyester technical fibers next to skin on our responsibly sourced Merino wool, long-sleeve base layer. By putting polyester next to the rider&';s skin, it transports moisture away to the Merino layer where it can evaporate even as the wool acts as insulation. The base layer uses a set-in sleeve design for a versatile form-following fit to make layering easy.