Takaji Kuroda found that we can create many more new patterns by utilizing Marangoni Effect to compress direction. Marbling in Europe other cuntries mainly use only expansion direction to make patterns. Fortunately, Suminagashi only uses tap water (unthickened), both direction of Marangony Effect(Expansion Copmression) can be effectively applied to color thin films which float on the surface of water.
Suimonga, Round: A round pattern(s) within Suimonga ia a hard thin film(s). These are made of dye or color liquid with very small amount of metaric compound as additive. Amount and material of additive is different each other based on its chemical characteristics.