The sageo is a cord — typically silk, cotton, or synthetic — threaded through the kurigata, the small knob on the side of the saya. Historically it was used to secure the saya to the wearer's obi (belt) or to bind the sword for carry. On a collectible or display piece, the sageo functions primarily as a finishing detail that completes the overall mounting aesthetic. White sageo in particular stands out for its strong visual contrast against darker saya finishes and its association with formal or ceremonial presentation styles in Japanese sword tradition. The material, width, and braiding style of the sageo all contribute to the finished look.