Forge-welding and folding steel bars to create a billet and forging it into a SUNOBE, then into a blade. Start by manipulating the pattern in the steel. This is not a foreign concept to the Japanese smith. They use it commonly to make mokume out of soft metals and some schools use it to enhance the visual appearance of the steel grain in their blades. The Gassan school created their ayasugi hada this way, this drawing shows a ladder pattern that creates the wavy look of the ayasugi hada.