I am not exactly sure what the thickness of the material is, suffice to say, it is probably 3 or 4 times THICKER than the garage sale signs, and MUCH more flexible, actually it seems to do exactly what you are showing, except that the piece I am playing with is substantially larger (and more difficult to manipulate).
I believe it is probably 1mm material, however, I didn't check that when I bought it, and I don't have the material in front of me at the moment. (At work). I will be sure to measure it when I get home.
At the very least, I can say that the Polypropylene that I have now is much easier to work with than the for sale signs. Not sure why... but it seems less likely to snap.
Is that Cement I posted ealier going to work with this stuf, u think Digi?