Interesting where your inspiration can come from. Last week my daughter and I were out shopping and we just happened to wander down an isle with a variety of home items, including one that caught my eye. It was $3, and I saw that it had some potential as a slingshot, so I bought it, made a few quick modifications and came up with this: The material, I think, is simply polycarbonate. It's not very think (only 3/16", just under 5mm), but is strong enough for a single layer of TBG. At full draw, it only has a small amount of flex. I haven't tried it with a double layer, but I think this material could handle it. So, what was this made from? Here you go: Just a simple, inexpensive over-the-door coat hanger! I cut off the curved ends and the metal bracket: Then simply sanded the edges with some 220 grit sandpaper to round things out a bit. Simple, quick, light-weight and thin. This is a slingshot you could easily pocket or throw in a pack. As for shooting, so far, it shoots great! I've shot everything from 1/4" and 3/8" steel to 1/2" marbles - they all seem to work just fine. I launched one marble from one end of my property to the other, about 150' (45 meters) and it made it the full distance. Funny thing is, before I joined this forum, I would have walked by this piece and never given it a second thought. Now I'm seeing possibilities everywhere. I'll say it again, this is a bad hobby!