Used often by artists and Cosplayers that create interpretations of objects, weapons, accessories and, in most cases, armor pieces out of foam materials and it's many variants under a commited cycle or not.
"Foamie" being the product
name that it's given to the
top used
type of them that you can find in the art alleys from your
local stores.
Fact being that it's actually named
EVA Foam or Ethylene Vinyl Acetate Copoplymer Foam, term heard often by individuals who partake in these arts.
Other instances of the foams used go by, but not all: Styrofoam, Polyethylene Foam & Upholstery Foam. Surprisingly, the
fair majority that you will find inside the work of many can be easily found on your households, just not prepared to create stuff with it.