Collapsibles are objects that fold out for use and then fold back in again to save space. They include anything from sofabeds to Swiss army knives, Japanese lanterns to fireman's hoses and many other things that are designed to help life run more smoothly. This text identifies 12 principles of collapsibility (stress, folding, creasing, bellows, assembling, hinging, rolling, sliding, nesting, inflation, fanning, concertinas) and looks at examples of each in turn, before examining collapsibility in furniture of all kinds, from chairs and tables to sofas and storage.