COPIC original, Sketch, Ciao and Wide markers are refillable using this fast-drying, permanent, non-toxic ink. COPIC ink is alcohol-based, does not dissolve toner and works well with watercolors and colored pencils. Just match the color number on the marker with the corresponding ink color number. Markers can be refilled with the handy refill booster attachment .The 25cc ink bottle has enough ink to refill any of the COPIC markers many times.