螺鈿 Raden / Mother-of-Pearl Inlay
What is Raden in Japanese Katana terminology?
This is a technique where shell patterns are cut out and pasted on the surface or inlaid, and then hardened with lacquer. ""Ra"" means shell, and ""Den"" means to scatter and embed. In Japan, it is said to have originated from Tang, China during the Nara period, and during the Heian period, it was used as a lacquer decoration technique along with Maki-e. The shells used include luminous shells, white butterfly shells, black butterfly shells, blue shells, abalone, and Akoya shells.