would be if it contained some kind of voids, as in glass spheres or plastic foam bits. I would readily agree that it would world fine if it consisted of a binder along with plastic foam bits throughout. Otherwise, I severely doubt it.

I have some insulating sealant at home that is a liquid in the can, but expands to several times its volume when released through the valve. It insulates very well, but it is NOT paint.

Suppose that somebody developed a paint on the same basis. It would consist of plastic with dissolved nitrous oxide or whatever. When sprayed from the can, it would expand into a thick cohesive foam that would cover a wall. This is clearly possible.

David F Mayer