Something else you might try is taking a walk through a few 'department' stores, looking at the packaging, not what's inside it. Lots of interesting possibilities, some of that stuff is strong enough for hulls, much less windows. Plastic folders in the 'school/office' departments, bakery, dry-goods, who knows? Odd shapes, toy department. Really odd 'looks', women's department! And with that, I'll quit.
- 'Doc