shoji are mounted on hinges in a doorframe, and open like a standard western door. Some are single doors, some double doors. Double doors, whether bifold doors or not, are termed ryōbiraki shoji (). Tsukuritsuke shoji (, "fixed shoji"), are often horizontal strips. Development and use Hashira-ma equipment Traditional Japanese buildings are post-and-lintel structures. They are built around vertical posts, connected by horizontal beams (rafters were traditionally the only structural member that was neither horizontal nor vertical). The rest of the structure is non-load-bearing. The roof completed, all but the cheapest buildings also added a raised plank floor (except in the kitchen). The remaining question was what to do with the space between the pillars, the hashira-ma (, ). The hashira-ma might be filled with fixed walls, in cheaper Japanese homes. For example, there might be lath-and-plaster walls, or in colder areas thatch walls; these are still used in rustic teahouses and historic buildings (see images). Bark-and-bamboo walls, clapboard, and board-and-batten walls were also used. Where affordable, though, the tendency was against permanent walls. Instead, openable or removable screens were used, and their type, number, and position adjusted according to the weather without and the activities within. These items can collectively be termed hashira-ma equipment. The technology of hashira-ma equipment has developed over time, and shoji were among those developments. Shoji have imposed constraints on other types of hashira-ma equipment: being translucent, non-waterproof, light, and fragile, they need protection, but they also need access to light. History Literally, shoji means "small obstructing thing" (; it might be translated as "screen"), and though this use is now obsolete, shoji was originally used for a variety of sight-obstructing panels, screens, or curtains, many portable, either free-standing or hung from lintels, used to divide the interior space of buildings (see List of partitions of traditional Japanese architecture). While shoji now exclusively means a translucent framework screen, and "fusuma" an opaque one, historic terminology is less clear-cut. Cloth-covered frame panels that fit between pillars (but did not yet slide in grooves) were invented in the 600s. They were used to screen bedrooms (like the curtains on a canopy bed), and called fusuma shoji (there were also bedclothes called "fusuma"). When paper came to be used instead of cloth, fusuma shoji were also called karakami shoji. From the late 1100s to the early 1200s, translucent cloth and paper shoji were called akari-shōji (), "illuminating shoji".