The blade of the Shippu Black is made of damascus stainless steel, renowned for its sharpness and durability, as well as for the impressive "water" patterns it creates, making each knife truly unique. 

More specifically, the core of the blade is made of the innovative Japanese VG10 stainless steel alloy, known for its hardness due to the cobalt it contains, which is surrounded by layers of damascus steel, thus enhancing the hardness and durability of the knife. 

Each Shippu Black is hand-sharpened by skilled Japanese craftsmen on both sides at 15°, to deliver an exceptionally sharp knife.

Its hardness level is 58 (±1) HRC (a knife with a hardness above 56 HRC is considered good).

Cuts are recommended to be made on wooden or plastic cutting surfaces. Glass, stone, and marble cutting surfaces are unsuitable as they may cause permanent damage to the knife blades.

Wash the knife with warm water before using it for the first time. After each use, make sure to wash the knife immediately (with a mild detergent) and dry it with a soft cloth. Especially if you have cut acidic foods, you should wash the knife immediately after use.

For your own safety, you should always wipe the knife away from your body and away from its edge, using a cloth or towel.

It is not recommended to wash it in the dishwasher but by hand, in order to protect its material and maintain its sharpness for a long time.

No matter how sharp a knife is at first, after some use it needs sharpening, something that you can achieve with a sharpener, sharpening stone, or honing rod.

You can tell if your knife cuts well with an easy test using the knife and a sheet of paper. A sharp knife can easily and cleanly cut through a sheet of paper. On the other hand, a knife that needs sharpening will struggle and its cutting will be jagged.

It is also advisable to sharpen your knives with a professional occasionally, to fix any damage to the blade's edge and to maintain sharpness.