The paper tubes used extensively as cores in toilet roles and the like are not only light and strong; they are also well-known for their reasonable price and as a recyclable material. For the past ten years, MUJI has been selling simple racks made of round paper tubes. This time, using square paper tubes ensures that they blend in with the walls of a room; a "wall" of storage space can be created. The production of square paper tubes was not easy; it became possible as a result of manufacturing technology that served to solve such problems as the twisting that occurs due to humidity and temperature. By combining parts, the tubes can be used in many applications, such as storage racks, partitions, wagons, tables and benches.