Bright, blendable colors in a brush. Labeling and coloring your artwork is easy: With the Koi Coloring Brush pens featuring a durable tip, you can quickly return to the original shape. These pens behave similarly to brushes, allowing for fine, medium, or bold strokes simply by adjusting the pressure on the tip. The odorless water-based solvent enables smooth blending and layering of colors. Koi Coloring Brushes are a convenient way to add vibrant colors to sketches, journals, cartoons, illustrations, or stamps. The 48 transparent ink colors can be easily mixed to create a wide range of shades and effects. Use the colorless blender pen or Koi water brushes to create seamless washes, layers, and color gradients.