The easiest and most simple system. The ink is filled direktly into the barrel, after having unscrewed the grip section. The use of the pipette, the eyedropper, gave the name. Most of the eyedropper pens had slip caps, not really tight ways of closing the pen. The pen shown right is an early type, featuring a tapered cap.

How to fill the eyedropper with a pipette is shown above. The feed (6) is the very early over-underfeed. Feed (4) is the later spoon feed, positioned only below the nib.