When you see streaking in your work, its time to refill your marker. One bottle of Copic Various ink will refill a Ciao marker 13 times, Sketch 8-10 times, Copic 7-9 times, or Wide markers 5-6 times. Simply match the color number with your marker color number; each ink will refill any of Copic's marker lines. The bottles are easy to use, either with the handy booster, or by dabbing the ink directly onto the nib. Use Copic tweezers to remove the nib, making refilling even faster.
Comments about Copic Copic Various Ink Refill: Cool Gray #7:
I use this product to refill my copic sketch markers. Cheaper than having to buy new markers.