These are hand forged, stainless steel painting knives from Seki City in Japan. This area of Japan was settled by master sword makers nearly 800 years ago, due to an abundance of natural resources for metal working. Each knife is hand forged from one piece of steel. They are tempered for good bounce and flexibility. They will become more flexible and a bit thinner with use (and therefore a bit sharper as well). Unlike cheaper knives that will flake, rust, and chip with use, these knives will last and last if taken care of properly. A superb tool for the artist who appreciates the finest in art materials.