 To support this A-shape, the plywood armrest, which is curved at a right angle (through high-frequency dielectric heating), is affixed to the upper section.The chair structure is strengthened further by the armrest being joined to the back panel.The slats that were set shallowly into the side element were not able to withstand abrupt burdens and so are replaced by perforated three-dimensionally bent plywood, shaped to the contours of the body.