I’ve just bought a new sofa – it looks great and is very comfortable – but I suspect the Marenco Sofa would be far better to sink into.
Designed in 1970 and reissued in 2007, the Marenco Sofa (named after designer Mario Marenco) is available as a two or three-seat version, with a plywood and metal structure and a covering of stress-resistant polyurethane foam. The cushions are removable – square ones for the back and rectangular for the armrests. It’s also very light to move around – down to that foam I expect.
Arflex have reissued the sofa, but it’s not the easiest thing to track down. You can find information via Italian Design 360 – but expect to pay around £5,200 for the three-seater.