High quality TOUCH TWIN refill inks will help keep your TOUCH longer. Universal for all markers, the alcohol-based ink is odorless, non-toxic, and permanent on most surfaces. Color consistency is guaranteed with each bottle. The dropper style tip makes it easy to refill markers and works will for drip effects. Measurements are marked on the bottle so you know exactly how much ink to use. One 20ml bottle of TOUCH Refill Ink will refill a TOUCH TWIN marker 6~7 times. Match the ink color number with your marker color number you wish to refill. Currently available in 96 of the most popular TOUCH TWIN colors.