Inkstone drops, also known as water droplets or book drops, are an ancient traditional cultural artifact used to store inkstone water for grinding ink. The emergence of inkstones is related to the use of brush and ink and the rise of calligraphy and painting. At the latest during the Eastern Jin Dynasty, various shapes of water bowls appeared. People found that when pouring water into inkstones with water bowls, the water flow was often excessive. Therefore, a tool that was easy to control the amount of water appeared, which was called inkstone drops. Inkstone drops, also known as water droplets, water sprays, book drops, toad sprays, etc. The one with a mouth is called "Shui Zhu", and the one without a mouth is called "Shui Cheng".