knickerhocker stool by cornelius comanns from germany
designer's own words:
One pressure resistant and one tension resistant material is needed for this stool. Plywood and aluminium in this case. The appropriate folded metal sheet is just glued together surface to surface with the wood. This leads to extreme stability without the need of any extra connection like screws or the like. A single stool can be used leaning very stable against e.g. a wall. Two of them can just be put into each other to stand free with the same stability.
The stool can be used leaning against e.g. a wall or free standing when two of them are being put into each other.
The stools are extremely stable equal if leaning against a wall or two of them standing free together.
Two pieces of plywood are being glued together surface to surface with a metal sheet. This is leading to extreme stability of the construction.