If it sank to the bottom, it would be classed as "sink-in-water incense" (the highest grade). If it partially sank and partially floated, it would be given the next grade down: zhan incense. The lowest grade of agarwood incense, which bobbed near the surface of the water, was known as huangshou (yellow-ripened) incense.
施起燻一邊將一塊純度百分百、通體烏亮的祖傳沉香塊丟進水中，一邊不忘說明，入水若沉者，名為「沉水香」；次之，半浮半沉者，名為「棧香」；再次，稍稍入水而漂於水面的，名為「黃熟香」。