I'm needing to reupholster my cushions even though they are in perfect shape, but they've been around since 1967. The thickness of my cushions are 6 inches and they are 4 feet long (I don't remember the width) but I'm going to reupholster them myself to save on cost. The huge cost is the foam because of the 6 inches. I guess I can go with 4 inch thickness to save money but then it wouldn't be original. What do you all think, 4 or 6 inches? Also, any place where I can pick up foam at?