How many kinds of inks are there in Four Treasures of the Study?

Our common inks are divided into lampblack ink and Song Yanmo ink. Oil smoke ink takes tung oil fume as raw material, and its ink color is black and shiny, which can show subtle changes in ink color and is most suitable for landscape painting; Pine smoke is dark and suitable for feathers and human hair. The quality of ink depends on the color first. The color of ink is purple, followed by black, cyan and gray. You can also hear voices. Good ink sounds clear when it is knocked, delicate when it is ground, heavy and slow when it is ground, and rough when it is ground.