Water brush pen set Ideal for watercolor painting and unique calligraphy. Whether you are using solid or powdered pigments, water-soluble, crayons, marker, pencil each stroke with keep smiling art supply with water brush pen will give you even and smooth coverage. For fine to board strokes, our water brush pen can create a variety of different results.  Size: 4mm,5mm,5mm(Broad) Fiber Body and Nylon Hair