Koi Colour Brush Set of 6 Use Koi Coloring Brush Pens for thin and bold brush strokes. Ideal for illustration, drawing, designing, sketching, journaling, architectural drawings, manga and comic art. 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. Blend easily to create a multitude of hues and effects.