It's a thick, waffle like material - though there is probably a better way to describe it! It's a really nice item to wear and I think could be styled in lots of ways. I wore it with jeans the other day, although I failed to snap any pics (bad blogger).
Topsy Curvy are getting some really nice items in, right up to a size 32. Head over their website and have a browse. What do you have your eyes on?