Holds in body heat, naturally wicks moisture Breathable to prevent overheating Light enough to layer under office attire 100% silk. Machine wash, delicate. Imported Warm by nature. Silk longies are a super light layer that works under everything – even tailored clothing. A natural insulator, silk’s hollow fibers are the key to its warming power. It holds in body heat, plus wicks away moisture. Wonderfully soft, you’ll love the way it feels next to your skin.