5 Types of Fountain Pen Filling Mechanisms

by Oct 19, 2022Blog0 comments

Fountain pens come in many colours, materials, inks and filling mechanisms. When people buy their first fountain pens, they will usually choose cartridges since it seems to be the easiest and safest choice. As time goes by, they will start eyeing other ink types and ink colours to increase their ink repertoire. This requires them to go out of their comfort zone and use other types of fountain pen filling mechanisms. 

Currently in the market, there are 5 types of fountain pen filling mechanisms: cartridges, converter, piston fill, vacuum fill and eyedropper. 

How come there are so many of it? I’m getting confused now.

Alright, don’t worry. After reading this article you will not be confused anymore and be able to pick which one is suitable for you.

Without further ado, let’s begin, shall we?

#1. Cartridges

types of fountain pen filling mechanisms - cartridge

The first from the list of types of fountain pen filling mechanisms is cartridges. It is the easiest ink filling mechanism and it comes in tube form that holds a small amount of ink. Some companies produce their own proprietary cartridges, for example, a Lamy fountain pen cartridge can only be used on certain Lamy fountain pens such as Lamy Safari, Lamy Al-Star & Lamy LX fountain pens. 

Alright, but are there other alternative of cartridges that can be used in wide range of fountain pens?

Of course, companies such as Diamine, TWSBI and Monteverde produce standard, international cartridges (it usually measures at 38 mm with 0.8 ml ink capacity) that can be used in many fountain pens that accept standard international cartridges . Moreover, they come in many colour varieties, which allows you to have versatile ink library and storing them will be easy.

Isn’t it exciting?

#2. Converter

fountain pen filling mechanism converter

The second one is a converter, which is available in several types:

  • piston converter that has a twist mechanism to draw ink,
  • squeeze converter that has a press mechanism to draw ink, and
  • push-button converter (e.g. PIlot CON-70 Converter) where, according to Unsharpen.com, it works by pushing down the button at the top and the ink will be sucked into the body of the converter.

By using a converter, you can use any ink that you want from ink bottles, be it scented ink, dye ink, bulletproof ink, etc. Moreover, it can be attached or detached from fountain pens, easier to clean and if it is broken, it can be replaced. 

Music to your ears, right?

However, do note that each brand has its own proprietary converter that comes in different sizes and ink capacities. 

Moreover, notable fountain pens that use converters are Lamy Safari, Lamy Al-Star, Kaweco Sport, Pilot Kakuno, Pilot Metropolitan, Platinum Preppy, and many more.

#3. Piston Fill

fountain pen filling mechanism piston fill

The third one from the list of types of fountain pen filling mechanisms is piston, which has a twist mechanism to draw ink from ink bottles and usually comes built-in with some fountain pens such as TWSBI Eco, Pilot Custom Heritage 92, and Noodler’s Ahab Flex. 

The benefit of this filling mechanism is that it allows more ink capacity, more than 1.5 ml, which means longer time between fill-ups, perfect if you  don’t change ink frequently. 

In addition, the piston itself is easy to clean. 

Oooh, this sounds like a great filling mechanism.

However, since it is built into the body of fountain pens, cartridges cannot be used and if it is broken, it will be costly to repair.

#4. Vacuum Fill

fountain pen filling mechanism vacuum fill

Next is vacuum, which comes built-in with some fountain pens, such as TWSBI Vac700R and Pilot Custom 823. Usually to fill up a vacuum fountain pen, the knob at the end of the pen has to be unscrewed first, pull back the plunger and then push it back down. This creates a low air pressure environment in the ink chamber behind it. Once the plunger reaches the flared part of the ink chamber, the difference in air pressure will cause the ink to rush into the pen. 

Just like piston, it cannot use cartridges and it will be costly to repair if it is broken.

Then, what makes it different than piston fill?

Well, this type of fountain pen filling mechanism allows even greater ink capacity, more than piston, since it can fill up an entire barrel of fountain pens. 

Moreover, vacuum fill fountain pens tend to be sold at higher prices, something to be considered for before making a purchase.

#5. Eyedropper

fountain pen filling mechanism eyedropper

The last one from the list of types of fountain pen filling mechanisms is eyedropper, which essentially fills up an entire barrel of fountain pens with either an eyedropper, syringe, or pipette.

How come this is my first time knowing about this?

It’s because in the past, fountain pens were designed as eyedropper pens as the only filling mechanism. Now, most modern fountain pens are not suited to become one since there are holes present that need to be sealed with silicone grease to prevent any leaks coming out from the barrel of fountain pens. 

In addition, there should not be any exposed metal on the inside of the barrel.


With the advent of new technology, different types of fountain pen filling mechanisms have come to life. Choosing which one to use can be confusing at the beginning. 

However, don’t let it deter you from making a choice. 

You can try one for now and use it regularly. Soon, you will find yourself trying others too. 

Just enjoy the journey and have fun writing!