Quote - what you see there is a dome of plastic that is smooth on the outside, but ridged on the inside giving that pattern look.

that it something that would look best if modelled, but I might give it a go tonight, and see if I can come up with something at least similar in appearance using nodes (the tile node x 3 should work....)

OK, that's cool. Theres a challenge for you. I haven't seen anyone do something that looks right as of yet.