I'm hoping there are some foam experts on here. I bought foam for a camp bed a while ago and remember it was called things like grade A+ upholstery foam, extra dense blah blah blah. It's 4" thick and comfy enough but you do sink through to the floor if you're on your side.
My girlfriends making a sofa and we're looking for some foam to go underneath the cushions and struggling to work out what foam is actually super dense and what just calls itself that. I remember we used to have a 2 foot square cube of foam at work, if you sat on it you went in like 2 inches and it held it's shape. Does anyone know where we can find some really dense foam?