3.7 oz., 50% polyester, 25% ringspun cotton, 25% rayon. polyester retains shape, cotton comfortand rayon makes for a unique texture. Tri Oatmeal is 3.9 oz., 50% polyester, 37% ringpsun combed cotton, 13% rayon. form-fitting. side seamed
Note: the manufacturer says this shirt runs small, so purchase a size up from your normal size. also mentioned there
is some sheerness to the fabric, so keep that in mind when purchasing.