What is Matsukawa Hada in Japanese Katana terminology?

Matsukawa Hada or 松皮肌 in Japanese, refers to a type of pattern on the surface of the ground iron (jigane) of a Japanese sword. The term ""Matsukawa Hada"" literally translates to ""pine bark skin"", which describes the appearance of the pattern that resembles the texture of a pine tree's bark.

This pattern is characterized by a large Itame Hada (wood grain skin) with strong Chikei (black lines) appearing on the flat surface (Hira-Ji) of the sword. The rough and undulating texture of the pattern is reminiscent of the bark of a pine tree, hence the name ""Matsukawa Hada"".

Matsukawa Hada is particularly characteristic of the works of the swordsmith Norishige (則重), who was active in the Echizen province (now Fukui Prefecture) during the Kamakura period. Norishige is known to have followed the Soshu tradition, one of the major traditions of Japanese swordsmithing, known for its high-quality swords.

The pattern of the ground iron (jigane) plays a significant role in the aesthetics and value of a Japanese sword. It is one of the factors that sword connoisseurs look at when evaluating a sword. The Matsukawa Hada, with its unique pattern that resembles the texture of a pine tree's bark, is a distinctive feature that sets Norishige's swords apart.