Selected squirrel hair, sheep hair, and a small amount of synthetic fiber are mixed in a golden ratio, combining the super strong water storage of squirrel hair, the flexibility and elasticity of sheep hair, and the durability of synthetic fibers. One stroke coverage ensures even water retention without leaving any water marks. The same pen can switch between round tip details and flat brush coloring, allowing petals, water patterns, and architectural lines to be achieved in one step without the need for frequent pen changes. The pen belly is full and the pen tip is sharp, even after long-term large-scale rendering, the pen tip can still rebound instantly. Copper tube+double-layer crimping, without shedding or loosening; The pen holder is non slip and does not slip when sweaty.