I have a couple of those blue sleeping bag pads. One is polyurethane, one is polyolefin. PVC foam is used in PFD's.

Ethafoam is much more common in packing/general use than minicell, which I have only seen in boating applications.

> Hi Lee,

> The ethafoam that I have has cells that are .025" or smaller in size
> and it is rated @ 4 pound density. It is compressable and returns to 90%
> of thickness quickly with the final 10% returnes in a minute or so.
> "Firm white plastic with some give". Kinda hard to describe how
> something "feels" in text. As far as shaping, the ethafoam cuts
> well on a bandsaw and easily with a sharp knife. It resists sanding - just
> gets soft and fuzzy without really changing shape. Contact cement works
> well but the surface should be cleaned first [I use naptha]. I think it
> would make a comfy seat. I am going to try "hot wire carving"
> some ethafoam with a copper wire attached to a Weller soldering gun and
> "finishing" the surface with 80 grit sandpaper.

> I have some 1/2" thick blue "sleeping bag underpadding"
> that has a more rubbery feel [and is much softer] but I am not sure what
> it is - I would have guessed that it is an isocyanide [sp?]/ polyurethane
> based produce.

> Nobody has ever handed me a piece of foam and said "that is
> minicell" so I can't compare to it.

> Hank