Fountain Pen Filling Systems

The Complete Guide to Fountain Pen Filling Systems

This article may contain compensated links. Please read the disclaimer for more info.

Most beginner fountain pen users may not know that there are multiple types of pens with various fountain pen filling systems. The three filling systems are cartridges, converters, and built-in mechanisms. Each type has pros and cons, and the one you choose most likely depends on your experience level, how much cleaning and maintenance you wish to do, and your preference for other fountain pen characteristics such as brand or look.

Even if you know the different filling systems, you might need clarification on which type is best for you. So to help you, I’ve compiled a guide to fountain pen filling systems to explain each type and help you choose the best pen. So let’s get started.


Cartridges are small tube-like ink reservoirs. They come pre-filled, so they are easy to swap in and out with little mess and fussiness. They are the most convenient filling system and are great for those on the go, as you don’t have to bring ink bottles or worry about filling your pens out and about. 

Ink cartridges are sealed tightly, making them easy and stress-free to transport. Once inserted into the pen, the open end is punctured to allow the ink to flow out of the cartridge and down to the nib. Read our guide on How Fountain Pens Work for more information.

Cartridges come in two main sizes: Standard International and proprietary. Standard International cartridges come in long and short formats while proprietary cartridges are made to a manufacturer’s exact specifications. To ensure you buy the correct cartridge, consult out Cartridge Compatibility Guide.


  • Lightweight and portable.
  • Simple to use.
  • Least messy option for filling systems.


  • Can be the most expensive option.
  • Less flexibility for changing ink types.
  • Creates waste with plastic cartridges.
  • Low ink capacity.

Pen Options

Also check out our post on the Top Fountain Pens for Beginners.

How to Fill a Fountain Pen with a Cartridge

Installing a fountain pen converter is pretty simple. 

  1. Locate the correct end of the pen that will be inserted and insert it into the grip section. 
  2. Press the cartridge into the nib firmly until the cartridge is punctured. 
  3. Point the nib down and allow the ink to saturate the nib for ideally 1-2 hours.

For a more in-depth tutorial, see our guide on How to Install a Fountain Pen Cartridge.

fountain Pen Converters


The next option for filling systems is the converter. Converters are essentially reusable cartridges. They look very similar to cartridges but can be filled with fountain pen ink. Converters are a great option for those that want to test out different inks but don’t want to buy a completely new pen, as converters can be used on any pen that takes cartridges (as long as you buy the correct type of converter). 

Converters typically come in three types: piston, squeeze, and push-button varieties. All filling mechanisms work the same way, but how you fill them is slightly different. 


  • Most cartridge pens can be used with converters.
  • Allows your cartridge pens to hold a variety of inks.


  • Smaller ink capacity than built-in systems.
  • Not all converters are compatible with all pens.


Piston converters are the most common type. There are two types of piston converters: twist and plunger. The twist converter works by twisting the knob at the base of the converter, moving the piston up and down to create a vacuum, drawing ink into the pen. For the plunger, it works the same way a syringe does. As you pull up on the plunger, the vacuum draws ink inside.

Twist Converter Options

Plunger Converter Options


Squeeze converters use the squeeze mechanism to draw ink in and out of the converter to create a vacuum. This draws ink into the converter in a similar way to a piston converter.

Squeeze Converter Options


The least common type of converter is the push-button. They are a great option to hold more ink than other types but are more challenging to use and harder to clean.

Push- Button Converter Options

How to Fill a Fountain Pen Converter

Filling a fountain pen converter is trickier than inserting a cartridge, but with a little explanation, it’s very easy. For simplicity, I’ll be explaining how to use a piston converter. If you have another converter, read here for help filling those. 

  1. Insert the converter into the grip section like a cartridge. 
  2. With the piston fully raised, dip the entire nib into the ink bottle. 
  3. Twist the knob to lower the piston, expelling air from the converter. 
  4. Twist the knob the opposite way to raise the piston to fill the converter with ink. 
  5. Repeat steps three and four until the chamber is completely filled with ink.
  6. Blot the nib with a paper towel to remove any excess ink.

For a more in-depth look, check out our guide on How to Fill a Foutain Pen Converter.

Fountain Pen Internal Filling System

Internal Filling Systems

The final fountain pen filling system is an internal system. This works similarly to a converter, except it is, obviously, not removable. There are two major internal systems that you’ll come across when buying a fountain pen. The piston and vacuum. There are also eyedropper pens that, while not actually a filling system, is a different way to get ink into a pen for use.


  • Can choose any fountain pen ink to fill with.
  • Larger capacity than cartridges or converters.


  • More expensive.
  • Less versatile as you can’t use cartridges for ease.
TWSBI Fountain Pen

Piston Fountain Pens

Piston systems are the most common type of internal filling system. They work by twisting a knob at the end of the pen which moves the piston up and down to create a vacuum to draw ink into the pen.

Pen Options

vacuum filler fountain pen

Vacuum Fountain Pens

For vacuum fountain pens, a plunger is used to create a vacuum in a similar way to the piston. But instead of twisting, you simply push and pull the plunger until the barrel is filled. 

Pen Options

How to do a fountain pen eyedropper conversion

Eyedropper Fountain Pens

It’s possible to make almost any fountain pen into an eyedropper pen by simply filling the barrel with ink. However, the barrel must be airtight to prevent leakage, and not all converter/cartridge pens would work. Therefore, it’s a good idea to choose a fountain pen specifically made to be an eyedropper pen to ensure fewer leaks for damage to the pen’s components. This was a very common type of, and actually the only, fountain pen at one point. So, those looking for vintage fountain pen filling systems will want to use eyedropper pens. See how to do an eyedropper conversion, Here.


  • The largest ink capacity of all fountain pens.
  • Wide variety of ink choices.


  • Prone to leaks.
  • Needs more maintenance than other systems.
  • Not for beginner fountain pen users.
  • Less portable.

Pen Options

Fountain Pen Internal Filling System

How to Fill an Internal Fountain Pen Filling System

I will explain how to fill a piston and vacuum systems and give a quick overview of the eyedropper type. However, you can learn more and get more in-depth info from our guide.


  1. Dip the entire nib into the ink bottle.
  2. Twist the knob at the end of the pen to lower the piston and push the air out.
  3. Twist the knob in the other direction to draw ink into the pen. 
  4. Continue filling and unfilling the pen until the pen is completely filled.
  5. Gently dab any excess ink off the nib, and you’re ready to write. 


  1. Unscrew the nob at the end of the pen and pull back the plunger. 
  2. Insert the nib into the ink bottle and push the plunger down to create low air pressure in the chamber.
  3. The barrel will slowly fill with ink from the vacuum.
  4. Gently wipe away excess ink off the nib and replace the nob at the end of the pen.

For help, see my guide on How to Fill a Fountain Pen.


  1. Unscrew the fountain pen barrel.
  2. Coat the threads of the grip with silicone grease to help make a watertight seal.
  3. Using an eyedropper, fill the barrel up with ink until just before the threads. 
  4. Carefully reassemble the pen.
  5. Let the pen rest nib-down for a few minutes to saturate the feed.

For more help, see our guide on how to do an eyedropper conversion.

So there it is, the guide to all fountain pen filling systems. These different options are one of the most confusing for new fountain pen users but are what truly makes fountain pens so special because of how versatile they are and how you can truly create a writing experience that fits your needs. 

If you have any questions, leave your comments below or check out our other fountain pen posts for more help and inspiration. Even if you don’t have any questions, leave us a comment telling us your favorite filling mechanism. Do you like cartridge fountain pens, converter fountain pens, or do you go for a fountain pen with built-in filling system?

More Fountain Pen Posts

Spread the love

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *