It baffles me why Uni’s Jetstream Ink still hasn’t caught on as the default ballpoint pen ink outside of Japan. For those not in the know, the Uni Jetstream is the original “hybrid gel” or “low viscosity” ballpoint pen, which combines the smoothness of a gel pen with the write-anywhere capability and quick-dry features of a standard ballpoint. For me, the Jetstream has everything you would want in a refill: It writes a dark, solid line. It flows well. It dries nearly instantaneously and does not smear. Importantly, it works reliably in a range of tip sizes, from .38mm all the way up to 1.0mm. Yet we are still largely forced to import pretty much everything other than standard disposable Jetstreams click pens from Japan, despite Uni manufacturing a multitude of different refill formats that fit not just Uni pens but third-party brands.
I have new and vintage Lamy ballpoints, and the M17 refill works well in both of them. Shown here is the Lamy Unic (“Unicorn”? - now discontinued), as well as a standard Safari.
The much-publicized, Japan-only 2025 release of the Uni Jetstream M17 ballpoint refill - designed to fit M16-compatible Lamy pens, merely reinforces the absurdity of this situation. Look, I don’t mind the standard Lamy M16 ballpoint refill. There may have been some spotty QC years ago, and the current version is quite good, but it remains a standard ballpoint writing experience that’s never going to rise above the limitations of that technology. By adding the Jetstream ink, the M17 refill improves the writing experience significantly. But as with other Jetstream formats, there’s still no indication that this refill will be consistently available to markets outside of Japan. In the Japanese market, retailers now have a Safari Ballpoint option with “Jetstream Inside”, i.e. the Jetstream refill is included with the pen. Yeah, that probably won’t happen here. But I hope I’m wrong. :)
Many love the black Jetstream refills for their solid black line.
Takeaways and Where to Buy
I won’t beat the Jetstream drum any more than I already have. I especially love the Jetstream Multi Pens - mainly because they’re the way to get colors other than black - and Uni recently released an even smoother Jetstream ink (the “Lite Touch”) that some believe outperforms the original formulation. Most of my personal pens that take Parker-style refills now use the SXR-600, and my Lamy 2000 Multi Pen (4-Color Ballpoint) has long held the SXR-200 D1 refills. I’m a bit worried about falling too hard for the M17, because I don’t know how stable the supply will be given the current trade situation, but for right now I’m going to enjoy what I have. If you’re a Lamy fan and want to up your ballpoint game, grab some of them if you have the opportunity.
Only one part of our Jetstream selection!
Our store carries a wide variety of Jetstream pens as well as refills in as many formats as we are able to source. We still have a few Uni M17 refills in stock from the small shipment I managed to source. (Update: These are now sold out.) I'll try to find more, but timing of a resupply is uncertain at best. Stay tuned!
If you’re ever in the Nashville, Tennessee area, please stop in and see us! We’d love to welcome you in store and answer any questions you may have. The Gentleman Stationer is open this week Thursday (1-4) and Friday (1-6) and Saturday from 10-4. Our site is entirely self-supported through the shop and the T.G.S. Patreon Program.