About gofun.
Many types of pigments were once brought to Japan from China, and the pigment known as gofun in Japan originally denoted white-lead pigment. However, due to the humid environment of japan, white lead would turn black, thus making it difficult for this pigment to remain white. Over the centuries, oyster shells gradually replaced white lead as the raw material for making white pigment. Today, gofun conntinues to be used as white pigment in traditional art and craft.
First, gofun powder is placed inside a mortar and crushed with a pestle.