As ingenious as it is handsome, this flat-pack bookcase is assembled without screws or tools. Jam takes its cue from the natural law of gravity as friction holds the shelves in place via plastic wedges which are also an intrinsic part of the design. Hanover studio Rudolph Schelling Webermann softens the visual mass with rounded corners on the shelves and the bookcase can be placed against a wall or used as a freestanding piece.