While looking for something else entirely, I came across the "Kali"
tiling pattern generator for Classic MacOS. It creates patterns
based on the 17 different plane symmetry groups. Within about five
minutes of initial tinkering with it I came up with this:

http://www.campin.me.uk/Pix/KaliHex.gif

which looks like it ought to have potential as a quilt design,
albeit not that easy to machine-piece.

I couldn't get Kali to run on the Classic environment on MacOS X.

The software (along with other things that run on other and more
modern operating systems) is at

http://www.geometrygames.org

==== j a c k at c a m p i n . m e . u k === http://www.campin.me.uk ====
Jack Campin, 11 Third St, Newtongrange EH22 4PU, Scotland == mob 07800 739 557
CD-ROMs and free stuff: Scottish music, food intolerance, and Mac logic fonts