Hello! The full picture is at
http://img837.imageshack.us/i/isisquiltfinalphoto1.jpg/. I made it for the UK 2010 Hoffman Challenge, and to my delight it won. It was great fun to make and I show it off at every conceivable opportunity! I keep a quilting blog at
http://lobsterdesigns.dreamwidth.org/, some of the pictures have vanished (curse you, LiveJournal photo hosting) but most of my quilts are still visible.
I'm thinking of changing the direction for the lines in the top part of the shell, after looking at some real nautilus shells, so I'll put up a photo of that sooner or later. Of course, I've just sketched it and I'm not sure whether I like it. However, one thing I have decided is a good idea is to use a medium copper brown thread over the bottom half of the shell and cream thread over the top half.
For some reason, I just don't like clamshells. No idea why. Which wave pattern did you have in mind?