polyester; the fabric of our color block tops is soft, stretchy and breathable; great quality material will give you a relaxed feeling color block tops, long sleeve tunic, round neck shirts, casual, cute and stylish. color block design is classic and never out of the date. the stitching of classic colors has a strong contrast, which makes you look more cute and attractive. suitable for casual daily, home, work, travel, party, date, vacation, shopping, clubbing, etc. the material is not thin and thick, you can wear the color block tunic tops in spring,and fall . the long sleeve tunic tops is great pair with leggings, jeans, casual pants, boots for a chic look. you must get lots of compliments when you wear this long sleeve color block tops. also can wear it under a coat or jacket during winter. best gifts for women and girls. machine washable, wash in cold water and do not bleach, hang or line dry. please refer to the size chart before ordering. any other questions, please tell us freely