I just checked my label, 95% Modal, 5% spandex, sorry quiltsRfun
Quilty-Louise, it wouldn't kill you to try them, I bought a large because I'm so Junoesque, but I think a medium would fit, my bust size is 44+ so the 3X might work for you?
Not that I'm flogging anything for Target, but it is fun to have something in common.