To see the blade construction of a Japanese sword is not always easy. One way to understand the terminology is to look at cross sections of the blades. The drawings below assume perfect construction and this is never true. The layers can migrate into each other and show through when polished many times. An example would be Hizen Blades that are a two piece construction. When the layers are not perfectly even the thickness from the skin into the inner layer can be different on both sides. In general the higher quality swords have a more complicated construction.