Coreless

The classic example is layering 1084 carbon steel with 15N20 Nickel steel, which is employed by most American blade smith. But in Japan, due to the time-consuming nature of forging a Damascus billet, the coreless construction are rarely seen except on the extremely expensive collector pieces, sometimes priced over the prestigious Honyaki.

Common composition of Japanese coreless are Blue 2 mixed with White 2, the difference in alloy content allows them to form some contrast when etched under controlled condition. More exotic coreless knife may have Blue/White 1 added in to create different shades, there are remarkable pieces from masters like Shoichi Hashimoto mixing 13 different steel and few iron into Damascus to create pattern that is out of this world. Thus, the coreless knife tend to be less seen and highly collectable in the landscape of Japanese knives.