Pen refills: how to choose the right format, ink and nib

A pen refill may seem like an insignificant purchase. However, choosing the wrong reference can make your pen unusable, cause leaks or make writing uncomfortable. This applies to students, employees, teachers and users of Waterman, Parker or STABILO pens alike.

Before placing your order, three mistakes are particularly common:

• Choosing the wrong type of pen: a ballpoint refill will not fit a rollerball pen, while a fountain pen cartridge cannot replace a conventional refill.
• Underestimating the importance of the format: the word ‘standard’ alone does not guarantee compatibility with your model.
• Choosing based solely on colour: black or blue is not the only consideration. The nib width, type of ink and number of refills all directly affect everyday comfort.

What to check before buying a pen refill

1. Identify the pen mechanism

Start by determining whether it is a ballpoint pen, rollerball pen or fountain pen.

• A ballpoint refill generally contains paste ink and a ball at the tip. It is suitable for pens with a push-button mechanism or cap designed for this format.
• A rollerball refill uses more fluid ink and a tip that provides a smoother writing feel.
• A fountain pen cartridge fits inside the pen body and supplies ink to the nib. Depending on the model, the ink is delivered through the feed system or by means of a converter.

The shape of the used refill is a useful first clue, but the pen reference and the manufacturer’s information remain the most reliable ways to check compatibility.

2. Check compatibility and format

Not all brands use the same dimensions. A Waterman refill is designed for compatible Waterman ballpoint or rollerball pens, while a Parker refill must be selected according to the Parker mechanism concerned.

For a fountain pen, check in particular:

• the short or long international standard format;
• the cartridge length;
• the diameter of the tip;
• the stated compatibility with your pen model.

For example, Waterman ink cartridges in the short international standard format are sold in boxes of six. Long versions provide a different ink capacity and must not be confused with short formats when making your purchase.

3. Choose the colour and nib width

The colour depends on how you intend to use the pen:

• Black ink: professional correspondence, signatures and documents requiring a smart, understated appearance;
• Blue ink: note-taking, schoolwork and everyday use;
• Erasable blue ink: practical for corrections, provided you use a suitable eraser and bear in mind the limitations around document preservation.

A medium nib produces a clear, versatile line. A fine nib is better suited to precise annotations, narrow line spacing and compact handwriting. The stated widths are nevertheless indicative and may vary from one product to another: some references list approximately 0.7 mm for a medium nib and 0.5 mm for a fine nib.

Our selection based on how you use your pen

Recommended for:  Beginners on a budget

STABILO EASYoriginal refills – medium point – pack of 6 – blue (erasable ink)

Why this choice suits this profile: This pack of six refills is suitable for taking notes in lessons and for regular exercises. The erasable blue ink and 0.5 mm medium point cover everyday writing needs.

How this product helps you avoid the pitfall

The listing clearly specifies the EASYoriginal model, line width, colour, erasable ink and pack size.

Main benefit and key features

Six refills, a 0.5 mm medium point and a fresh tip every time you replace it.

Recommended for:  Premium pen enthusiasts

WATERMAN rollerball refill – fine tip – black ink – blister pack of 1 refill

Why this choice suits this profile: This Waterman rollerball refill with black ink is ideal for anyone looking for a fine tip for correspondence, signatures and detailed writing.

How this product helps you avoid the pitfall

The rollerball type, 0.5 mm fine tip and Waterman compatibility are clearly stated.

Main benefit and key features

Liquid black ink, a fine tip and individual blister packaging.

Recommended for:  Specific uses and intensive users

Parker erasable blue ink cartridges

Why this choice suits this profile: These five long Parker cartridges are suitable for frequent use with a compatible fountain pen, particularly for note-taking and correspondence.

How this product helps you avoid the pitfall

The long format, Parker compatibility, quantity and erasable ink are stated before purchase.

Main benefit and key features

Pack of five cartridges, erasable blue ink and a long format for compatible Parker fountain pens.

Recommended for:  Signatures and everyday writing

WATERMAN ballpoint refill – medium point – black ink – blister pack of 1 refill

Why this choice suits this profile: This Waterman ballpoint refill with a medium point is designed for office writing, signatures and documents requiring a clearly visible black line.

How this product helps you avoid the pitfall

The listing clearly distinguishes a ballpoint pen from a rollerball pen and specifies the approximately 0.7 mm medium point.

Main benefit and key features

Fast-drying black ink described as smudge-resistant, an individual refill and stated manufacture in France.

Installation and storage: best practice

To replace a refill:

1. Unscrew or open the pen body, depending on its mechanism.
2. Remove the empty refill without forcing it.
3. Insert the new refill the right way round.
4. Close the pen, then make a few strokes on a scrap piece of paper.

When using a fountain pen cartridge, wait a few minutes after installation so that the ink can reach the nib properly. Store refills in a dry place, away from sunlight and extreme temperatures. Inks can stain fabrics and porous surfaces: keep them out of the reach of young children.

Frequently asked questions about pen refills

How can I tell whether a refill is compatible with my pen ?

Start by checking the type of pen, brand and model. Then compare the shape, length and tip of the refill. For a fountain pen, look specifically for the wording fountain pen refill in the international standard format or the format specified by the manufacturer. If in doubt, the reference printed on the old cartridge provides a very useful point of comparison.

What is the difference between a fine point and a medium point ?

A fine point generally produces a narrower line, making it suitable for annotations and small lettering. A medium point creates a more pronounced line, which is often preferred for notes and everyday writing. The actual width can vary depending on the mechanism, so check the product listing.

Are erasable ink cartridges suitable for official documents ?

Erasable ink cartridges are useful for exercises, rough work and notes that may need correcting. For a signature or a document intended for long-term storage, choose permanent ink if required by the recipient. Erasable ink may disappear or change when exposed to an eraser, heat or certain storage conditions.