We offer several types of steel in our web shop. A special stainless steel developed for Sakai knife making. White steel one of the purest Japanese steels on the market and Blue steel. White steel is just a bit softer than blue steel and very pure. A perfect blend of pure iron ore and carbon. You don't have to understand Japanese to see the difference. The blacksmiths of Sakai use a simple pattern on the backs of their knives. Notice the two photos below.
White steel you see a straight line almost parallel with the spine of the knife.
Blue steel you see a wavy line almost parallel with the spine of the knife.