In my quest for a better pen, one of the better looking and incredibly balanced pen is the Waterman. However, my desire to hack the Waterman to greater heights cannot be restricted to mundane things like “oh - you cannot do stuff with a rollerball”.

The Waterman takes what is called the “Euro-format rollerball” refills. These are refills that are interchangeable between Coles, Diplomat, Faber-Castell, Graf von Faber-Castell, Laban, Ohto, Online, Otto Hutt, Platinum, Sheaffer, Waterman, Worther, Yard-o-led. It is also known as the “Pilot style G2” refill.. not to be confused with the “Parker G2” refill style.

This is a pretty cool list of the compatibility types.

Now the two best candidates that you can get in India in these styles is the Pentel Energel, which is by far the best rollerball refill I have ever used… as good as an ink pen. The other alternative is a Uniball Signo 207 - which is bloody damn good, but not as good as the Energel.

However, the Signo 207 has a special advantage - it is an indelible, waterproof ink that is intended for documents. So I finally chose the Signo. If you do not have a Buffet-esque need to sign documents, then please go ahead and use the Energel.

Now the trick is this - the Signo and the Energel are both longer than the original Waterman refill, if you match the tips together. Do NOT, repeat NOT, cut it to the same length. Cut the Signo/Energel a little bit longer, maybe a quarter of an inch. Because of the way they are both designed, the new refills need that extra length.

The energel or the signo 207 refills cost rupees 50. The original waterman refills cost 1500 rs.

EDIT: 30 April 2023 - turns out that the Signo refills are good enough for the Mont Blanc Starwalker-style Fineliner (felt tip refills) or the Mont Blanc Rollerball. Both the Mont Blanc Fineliner and Rollerball refills are interchangeable anyhow. However, they have a screw threading. The Signo does NOT have a threaded refill. However, it doesnt stop it from fitting perfectly. The Signo refill may be a hair too short - so the way to do it is like in this video.

1. First take an old mont blanc refill (or a thin eraser refill). and put either of them at the back of the mont blanc barrell
2. take a very small piece of tape and roll it around the bottom portion of the tip. This is just to prevent the refill from wobbling since it doesnt have threads.
3. cut the new Signo (or any G2 style refill) to account for the rubber/plastic you put in the back of the barrell
4. thats it!

It works and i daresay its MUCH MUCH better than the original mont blanc refill. The Signo 307 87-E refills are unbelievably good. And remember they are security refills (cannot be washed off)