What is Nie-deki in Japanese Katana terminology?
Nie-deki refers to a type of blade pattern (Hamon) in Japanese swords. ""匂"" (Nie) refers to the tiny crystals that appear in the blade pattern (Hamon), which are so small that they cannot be seen with the naked eye. Among the blade pattern (Hamon)s that appear in swords, those with a strong presence of Nie are called ""匂出来"" (Nie-deki).
This discernment can provide important clues about the sword's origin, the era in which it was made, and the techniques used by the swordsmith. The presence of Nie in the blade pattern (Hamon) is considered a crucial factor in evaluating the quality of a Japanese sword.