Have you tried a soft sports bra or sleep bra? They are quite comfortable and soft. I don't think the shelf bra has much support (thinking of the ones in bathing suits) but the shirt would have to be quite snug to keep you in there. What is RSD?

Threads Magazine issue #109, October/November, 2003 has instructions on how to make a shelf bra. You can order back issues of their articles on their website, Threadsmagazine.com. I would send you the article, but my subscription doesn't go back that far (sorry).

Mary L

Here is a link that might be useful: http://www.taunton.com/store/pages/th_toc_109.asp