On Mon, 02 Nov 2015 17:53:43 -0700, Don Y
wrote:

All this talk about (expanding) foam...

I've been looking for some PARTICULAR (pre-expanded) foam to line some
"equipment cases". I have several such cases designed for specific
bits of equipment that utilize this foam. So, you'd *think* it should
be available SOMEWHERE???!

The foam is *black*. No, not grey. Also, it's not the sort of foam
you encounter at craft stores (regardless of color). It's more like
styrofoam in its makeup -- less "homogenous" than that craft store
foam.

If you think about styrofoam, it's sort of like little chunks that
are stuck together; you can pull off these little chunks "intact".

FTR, you're not describing styrofoam. You are describing some newer
product. Styrofoam is a mixture of styrene plastic and air and it's
crushable but prior to crushing it's hard, and the walls (surrounding
the air bubbles) are all one piece, the length and breadth and
thickness. Nothing can be pulled off.

I only mention this to help you describe what you want.

Also, one of the replies you got showed camera cases and said the foam
could be cut with a utility knife. I'm sure that's true if they say
so, for black foam. For foam rubber otoh, it's really hard to cut
with a knife but an electric knife, like for cutting the turkey, works
very well.