Coloring your artwork is easy, anywhere, anytime with the no-mess, dye-based, 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 facilitates smooth blending and layering of colors. Koi coloring brushes are a convenient way to add vibrant color to any sketch, journal, cartoon, illustration or rubber stamps. Use the colorless blender pen to create seamless washes and color gradations. Applicable for illustration, journaling, sketching, rubber stamping, architectural drawings and manga/comic art. Technical qualities are flexible nylon nib, Odorless, water-based solvent facilitates easy blending, 24 color sets packaged in a reusable plastic case with front clasp. The 24 color set is organized in a durable, translucent storage box from ArtBin, dye based ink, for best results, use on a heavy weight, plate-finish paper (smooth but not coated).