Hamon is a distinctive pattern found on the blade of a traditional Japanese sword, known as a katana. This pattern is created during the forging process, where different types of steel are layered and treated to produce a hard edge and a softer spine. The result is not only functional, enhancing the sword's performance, but also visually striking, making each blade unique. The appearance of hamon can vary widely, influenced by the techniques used by the swordsmith, or tosho. Common styles include the straight, wavy, or irregular lines that reflect the cooling process of the blade. Collectors and enthusiasts often appreciate hamon as a key aspect of a sword's artistry and craftsmanship.