Coloring your artwork is easy, anywhere, anytime with the no-mess Koi Coloring Brush pens. These pens perform similar to an artist brush. Make fine, medium or bold brush strokes just by changing the amount of pressure to the nib. The durable tip will quickly spring back to its original shape. The odorless, water-based solvent faciliates smooth blending and layering of colors. They are a convenient way to add vibrant color to any sketch, journal, cartoon, illustration, or rubber stamps.