This natural flat grinding Suzuri stone is 5 2 1/2 and is used with sumi ink sticks to create sumi ink for Sumi-e painting. The Suzuri is a flat grinding stone used to make Sumi Ink. It has a sloping indentation which forms a small well at one end. A Sumi ink stick is ground on the stone surface with plain water to produce liquid ink. To avoid unevenness, indentations and grooves, grind the ink over the entire surface of the stone. Never leave the ink stick on the wet stone surface. It will adhere and damage the stones surface. Wash the stone in plain water after each use. To preserve the surface of the stone, it is recommended that you wash the stone with your fingers.