Keep your Deep Iris color even and smooth by refilling the marker with the Marker Refill by Altenew. Included in the package is one 30 ml alcohol-based marker refill that can be used up to 10 times and is easy to use. Just remove the brush nib with a pair of tweezers, position the tip of the refill bottle right above the open barrel of the marker and fill the marker with 8-10 drops. Reinsert the old nib or replace with a new nib and you're done!