Rossette Women"s Cotton Thermal Undershirt is a luxurious, soft, and comfortable baselayer that maximizes silk"s body-insulating ability for moisture regulation. Incredibly strong, the cotton knit is supple and sumptuous with a natural stretch for all day comfort and an attractively-shaped pattern. Rated for very cold temperatures. 100% cotton under. Very comfortable and stretchable. Machine wash warm. Non- Chlorine bleach on white. No bleach on dark colors. Tumble dry low. Do not iron.