Castelli calls the Iride Seamless base layer their softest and most comfortable base layer to date. Castelli base layers are fast becoming some of the most popular because they are very soft next to the skin and form fitting with a perfect but very light compression so it almost "dissapears" when worn. Castelli achieves this with a state-of-the art seamless knitting technology and a moisture-wicking blend of polypropylene, nylon, and lycra.
To optimize moisture transport, Castelli uses a proven Polypro/Lycra fabric blend. Polypropylene is a popular choice for performance base layers, as the fabric's fibers quickly transport moisture away from your skin. Once the moisture has reached this point, the Iride's nylon layer takes over, transferring the moisture outward to the surface of the garment to evaporate there, keeping you warm and dry.