Sizes and Materials: Our maternity garments are available in One Size for pregnant women who are regularly sizes 2-10 and XXL for sizes above. We use American Apparel XL for our One Size. The tank tops are made of 2x1 ribbed, super stretchy 100% cotton. Washing Instructions: Preshrunk 100% cotton, made in the USA. Wash in inside out in cold water, hang to dry unless you want it to shrink a tad, in which case tumble dry low. Do not iron.