Sword Decoration

Almost all blades are decorated, although not all blades are decorated on the visible part of the blade. Once the blade is cool, and the mud is scraped off, the blade may have designs or grooves (hi or bo-hi) cut into it. One of the most important markings on the sword is performed here: the file markings. These are cut into the nakago or the hilt-section of the blade, where they will be covered by the tsuka later. The nakago is never supposed to be cleaned: doing this can reduce the value of the sword by half or more. The purpose is to show how well the blade steel ages.

Some other marks on the blade are aesthetic: dedications written in kanji as well as engravings called horimono depicting gods, dragons, or other acceptable beings. Some are more practical. The presence of a groove (the most basic type is called a hi) reduces the weight of the sword yet keeps its structural integrity and strength using the engineering principles of the I-beam.

In Japanese, the scabbard for a nihontō is referred to as a saya, and the handguard piece, often intricately designed as an individual work of art — especially in later years of the Edo period — was called the tsuba. Other aspects of the mountings (koshirae), such as the menuki (decorative grip swells), habaki (blade collar and scabbard wedge), fuchi and kashira (handle collar and cap), kozuka (small utility knife handle), kogai (decorative skewer-like implement), saya lacquer, and tsuka-ito (professional handle wrap, also named emaki), received similar levels of artistry.