What is Tsukurikomi in Japanese Katana terminology?

Tsukurikomi"" (造込み) refers to the three-dimensional representation of a sword's structure, including its cross-sectional shape. It encompasses various factors for consideration, such as the shape of the curve (sori), the presence or absence of a ridge line (shinogi), the thickness of different parts, and the structure of the back of the blade (mune).

Various forms such as Shinogi-zukuri (鎬造), Hirazukuri (平造), Hira-zukuri Kotogiri (片切刃造), Shobu-zukuri (菖蒲造), and Naginata-zukuri (薙刀造) were devised according to combat styles and preferences of different eras.

In addition, ""Tsukurikomi"" is also a term used to describe the process in sword-making where the outer steel (kawagane or hadagane) and the inner steel (shingane or core iron) are combined to form the shape of the sword.