These pads are made of three layers of bamboo fiber, microfiber and breathable membrane, washable, strong water absorption. The fabric is comfortable and soft, does not stimulate the skin, care for mommy and baby. The pads can effectively prevent milk overflow, leak-proof. They are designed to fit better in your nursing bra. Not too thick and not too thin and just the right size. Perfect for chafed or sore nipples and nursing mothers with sensitive skin.