5 oz., 100% combed ringspun cotton 1x1 baby rib; White is sewn with 100% cotton thread; Heather is 88% combed ringspun cotton, 12% polyester 1x1 baby rib; Flatlock seams; Double-needle ribbed binding on neck and shoulders; EasyTear labels; Sideseam construction; CPSIA compliant tracking label in sideseam; Raw serged sleeves and bottom