• The Basics
• Eyedroppers
• Retracting-nib safeties
• Lever-fillers
• Button-fillers
• Piston-fillers
• Crescent-fillers
• Twist-fillers
• Bulb-fillers
• Pump-fillers
• Vacumatics
• Plunger-fillers
• Blow-fillers
• Touchdowns/Pneumatics
• Snorkels & PFMs
• Capillary fillers

The standard filling mechanism for better European-made pens since the later 1930s, piston-fillers utilize a screw mechanism to move a piston inside the barrel, taking in and expelling ink.  The mechanism is typically actuated by turning a knob at the end of the barrel, although in some instances the turning knob is concealed underneath a blind cap.  While some piston-fillers incorporate a tip-dip feature, in most cases the nib must be fully immersed when filling, just as with other pens.

Montblanc piston-fillers made up until the early 1960s used a two-stage screw mechanism.  Very little resistance is felt for the first few turns, which sometimes fools the uninitiated into concluding the pen is broken.