A quoin has two distinct primary definitions depending on whether it is referenced in traditional architecture or historical printing technology. In architecture and masonry, a quoin refers to the external corner stones or bricks of a building, often intentionally accentuated in size, texture, or projection to provide structural reinforcement to load-bearing walls while imparting an aesthetically pleasing, refined visual boundary to the facade. In traditional letterpress printing, a quoin is a mechanical expanding wedge device used inside a chase to lock type securely into place before printing. Both uses share the underlying conceptual essence of stabilization, structural integrity, and locking components firmly together to withstand external pressure or operational forces.