Short sleeve. This way you won't sweat or make you uncomfortable during the day. The pajama bottoms provide a perfect fit thanks to the comfortable waistband. Cotton is a natural fiber Made from pure cellulose Cellulose is an organic substance created by synthesis in nature. It has low elasticity. Modal is made from beech wood. It's a natural fabric made from the cellulose of the beech tree. It has a first-class softness. Moisture transfer is fast. Care Instructions. Wash at max. 30°C. Do not tumble dry. Do not bleach.