More known in the US as bean bag chairs, the real name comes from the inventor, Sacco design in Norway. The chairs are, as the name implies, bag shaped chairs filled with a substance to form itself as a person uses the chair. The "beans" in the bag are small polystyrene pellets, the same substance that your computer used for travel protection (although compressed for that use). The bags are all same in form, but the sizes vary a bit. Patterns and colours are limited only by the sky.

Notes on Sacco bags: They get hot. The polystyrene is very insulating and will send the heat back to your body. Even more if you are naked. The bags get flat after a while. Sacco sells more polystyrene in the shop where you bought them, so you just open them and pour in more pellets. Two bags form a small sofa.