This is a slim elastic, but quite strong.  You could certainly use this for smaller sized bras, and possibly even more supportive ones.  The edge has been overcast with a satin thread, to give a slightly raised edge, and is designed to peak at the bottom of your fabric, so it is visible.  Almost like miniature piping!

Beautiful quality. Available in 3 different widths.  the sample set contains 1 metre of each size (08mm, 10mm, 12mm)