Bra Padding Foam
Bra padding is generally used to provide shape or boost to lingerie/corsets. It is a foam sandwiched between two softer fabrics.
It is possible to use the bra padding to make a bra cup in it's own right, simply binding edges and covering joins with lace trim. When joining the cup pieces, do not sew a conventional seam but butt the edges up together and over the join with seam tape to prevent bulk at the seams.