That fabric that looks and feels sort of like very thin neoprene....

[TheKimJongUnofFeminism]

.....does anyone know what it's called? I'm selling a dress of dd's on EBay and I don't know how to describe it. It was very fashionable a couple of years ago.

I think it’s generally described as ‘scuba’. I bought this jacket recently from cos which I think is in the same fabric you mean, and that’s what they have called it: www.cosstores.com/en_gbp/women/coats-and-jackets/product.short-scuba-jacket-with-hood-black.0545572002.html

Ah, thank you, that's it. Dd bought it and loved it-then discovered too late that against bare skin it set her teeth on edge!