In the art of xingshu, ink is not merely a medium but an active element that contributes to the expressive power of the calligraphy. This essay will delve into the technical aspects of ink control, examining how a calligrapher manages ink density, saturation, and dryness to create a diverse array of visual effects. We begin with a discussion of the properties of ink, highlighting how its consistency, from rich and dark to diluted and pale, can alter the character of the strokes. Understanding the material properties of ink is crucial for any calligrapher seeking mastery of the brush.