For thousands of years, sumi ink sticks have been made by mixing soot with glue to form solid blocks. They are ground on a Suzuri stone with water to produce ink in the way of traditional Asian artisans. Sumi ink sticks are unsurpassed for producing the famous Five Colors, or shades of black, that form the basis of monochromatic Sumi painting. The subtlety of Sumi ink is evident in the variety of tones and values it produces. The dot on the top of the Sumi stick indicates its quality and authenticity.