MUJI Warm Cotton Crew Neck Long Sleeve T-Shirt Set of 2 Color: Dark Gray Size: XL Material: Organic Cotton, Rayon This T-shirt is made with cotton that absorbs moisture from the body and generates heat. It has a thin and smooth feel. The cotton is organic cotton. This warm innerwear enhances the "moisture-absorbing and heat-generating power" by applying special technology to organic cotton, converting steam emitted from the body into heat. This year, we have further improved the material to make it warmer and more comfortable. We offer three types of warm cotton: thin, thick, and wool, allowing you to choose based on your needs. ■ Enhanced natural moisture-absorbing and heat-generating function of cotton Cotton is a natural functional material that absorbs moisture and generates heat. We have created moisture-absorbing and heat-generating innerwear that enhances its original function while maintaining the texture of cotton. The warmth lasts even after repeated washing. ■ Reduces skin dryness Compared to synthetic fibers, cotton does not excessively absorb the skin's oils, making it a gentle material for dry winter skin. ■ Combination of natural materials that suppress static electricity Synthetic fibers and different materials tend to generate static electricity. Cotton is less prone to static buildup and is a material that prevents static electricity even when layered with wool knitwear. ■ Features of Warm Cotton (Thin) This thin and smooth warm innerwear is comfortable to wear. It is less noticeable under outerwear and is comfortable for protection against the cold in the autumn and spring seasons, as well as indoors. Organic cotton is blended with rayon, a naturally derived cellulose fiber made from beech.