MTN Empty Marker - 3mm Empty Marker is a 3mm empty marker produced with a high-quality body and nib.  The perfect versatile empty paint marker to fill with Montana Ink refills or the paint refill of your choice.  Montana Colors Empty 3mm Marker has a pump action to give you control and allow for drips as needed in an ultra-thin line. It is a perfect paint marker for the graffiti artist on the run or in the studio.