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.