The Jetstream Is THAT Good: Hands on with the Uni M17 Lamy Refill

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.

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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. :)

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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.

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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.

Comparing Low Viscosity Ballpoint Pens: Jetstream vs. Acroball vs. Anterique vs. Ohto

It’s been interesting to see pen manufacturers - especially the Japanese manufacturers - move away from standard ballpoints to low viscosity refills. You sometimes hear these refills referred to as “hybrid gel-ballpoint”, because they combine the permanence and quick dry times of a classic ballpoint pen with the smoothness of a gel pen. Personally, I love them, and they form a core part of my own everyday writing rotation. The downside is that outside the Jetstream line, you don’t have many color options, with most companies offering these refills only in black.

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In order of darkness, I would rank the inks as follows: Pilot Acro Ink, Uni Jetstream, Anterique Mach Ball, and Ohto. In order of dry time, I would rank them the exact inverse: Ohto, Anterique Mach Ball, Uni Jetstream, and Pilot Acro Ink. That’s not to say that any of them “dry slowly,” but with a darker like, you will get more smoothness, and with that added smoothness comes increased dry time because it means more ink is on the page.

With so many of these sorts of pens entering the market, I thought it might be helpful to do a quick comparison of my thoughts on four of the most common brands: Pilot (Acro-Ink / Acroball), Uni (Jetstream), Ohto (various needle-tip refills), and Anterique (“Mach-ball”). See below for my thoughts on each. Please note that this post is not intended to be comprehensive, but rather an overview of the more popular refills that I often get asked about, with a focus on how they compare to one another. For a more general overview of low-viscosity ballpoints, including other brands, see this post here.

• Uni Jetstream. Probably the easiest to find of all the refills featured in this post, the Jetstream comes in anything from D1 size to Uni’s own proprietary multi-pen size to a standard Parker-style cartridge. The biggest selling point of the Jetstream is the number of options you have. D1 and multi pen refills come in colors that include black, blue, red, and green, and even though the Parker-style cartridges are available only in black, you still have .38mm, .5mm, and .7mm tip sizes. Jetstreams are smooth writers - maybe not quite as smooth as Pilot’s Acro-ink, but you’d have to be a pretty big ballpoint aficionado to notice the difference.

• Pilot Acro-Ink. In my opinion, the smoothest, easiest-writing refill on this list. While Pilot’s Acro-Ink refills aren’t quite as ubiquitous as the Jetstream line, I like them for longer-form writing. The .7mm writes a smooth line without smearing, and in my opinion it’s a better .7mm tip size than the Jetstream. These refills are found in the Pilot S20 ballpoints, the “Dr. Grip” line, and the Pilot “Acroball” pens that you can sometimes find in larger office supply stores.

• Anterique “Mach Ball” Refill. Anterique is known for taking the classic vintage-style click pen and upgrading it with their excellent refill. It only comes in one tip size (.5mm), with black ink, but it’s a great pen and relatively inexpensive. Pro tip: you can often substitute one of these refills into a standard vintage Bic Clic ballpoint. I have a large collection of vintage ballpoint pens, and it’s been a joy to give many of them a fresh life with a new refill. Sometimes you have to trim or extend the Anterique refill, as I don’t think the specs on the Clic were consistent over the years, but there are only a couple of exceptions where I was unable to make it work. Anterique’s biggest selling point is that it dries nearly instantaneously.

• Ohto Needle-Tip Ballpoint Refill. The ultra-precise .5mm needle-tip ballpoint has become Ohto’s hallmark. Of all the pens on this page, Ohto’s are on the drier side, but what this means is that you will get a very precise line and zero smearing. Ohto makes the refill for Object Index, Traveler’s Company, and Mark’style branded pens. Honestly, if you see any Japanese needle-tip ballpoint pen, chances are it’s an Ohto.

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Writing sample pens are, from left, the Pilot S20 (shown here in brown), the Anterique Mach Ball Standard Size, the Object Index Cedar Pen, and the Uni Jetstream 4+1 Bamboo.

I’m a huge fan of ballpoints and they play a huge role in my everyday working life because, well, they just work. We stock a wide variety in our shop, and if you come visit us in person, ask to try each of the refills featured here, as we have testers generally available.

Thank you for reading! The Gentleman Stationer is supported by the T.G.S. Curated Shop and the T.G.S. Patreon Program. If you’d like to visit our in-person location, you can view directions and up-to-date hours here.

Refill Hacks: Alternatives for the Caran d'Ache 849 Ballpoint

While I personally think the Caran d’Ache 849 “Goliath” refill that ships with every Caran d’Ache 849 ballpoint pen is a smooth, reliable, relatively dark refill that lasts a long time and, at the end of the day, gets the job done just fine, I understand that many of you are left wanting a different option for Caran d’Ache’s iconic click pen. The Goliath, however, is a proprietary refill with a slightly odd shape that makes it tricky to replace. Over the past few weeks, I’ve experimented and come away with three alternatives that work reasonably well.

Note: The hacks discussed below are just that, “hacks,” and not in any way a modification authorized by the manufacturer. While I’d personally consider the risk extremely low - especially with a ballpoint - if you break any pen by modifying the mechanism or using a non-standard refill, you will likely void your warranty. The same goes for modifying or grinding fountain pen nibs, feeds, etc. Proceed at your own risk!

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The Caran d’Ache 849 Rollerball Refill appears to fit most of the 849 ballpoint pens just fine, though if you get a refill that’s slightly too long, you can adjust using Option 2 below.

Option 1: The Caran d’Ache 849 Rollerball Refill

Many people were thrilled to see Caran d’Ache release a larger rollerball pen in the classic 849 profile. The best part about it? The 849 Rollerball uses a Parker-style rollerball refill - and a really good one at that - which comes in both .5mm and .7mm sizes, in black or blue ink. (The 849 Rollerball pen itself ships with a .7mm black rollerball cartridge.) While you can turn the 849 Rollerball into a larger ballpoint using any Parker-style refill, I’ve had very good luck with the inverse - the Caran d’Ache Parker-style rollerball cartridge also appears to fit the standard 849 ballpoint pen without much, if any, modification.

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Parker-Style refills such as the Jetstream SXR (in the yellow pen) and the Schmidt P900 (pictured here) can be made to work with a simple trick.

Option 2: The Jetstream SXR (and Most Other Parker-Style Ballpoint Refills)

One of my favorite ballpoint refills of all-time is the Uniball Jetstream SXR - a Parker-style low viscosity ballpoint refill that serves as one of my go-to Parker-style refills when I’m looking for an ultra-fine tip ballpoint that dries quickly. While it took a bit of work to get this particular cartridge to work in the standard Caran d’Ache 849 ballpoint pen, here’s what I did:

• Step One: Unscrew the knock at the back of the Caran d’Ache 849 and remove the Goliath refill.

• Step Two: Insert the Jetstream SXR (or Schmidt P900 or Easyflow 9000 or other Parker-style ballpoint refill of your choice).

• Step Three: Replace the knock and screw it all the way down until you reach the end of the threads. You will likely have one of two issues: (1) when you retract the refill, the tip still extends past the end of the barrel, since the refill is too long; and/or (2) when you try to depress the knock, the refill won’t “catch” and stay in writing mode. To fix both of these problems, I typically unscrew the knock one or two turns, which pulls the tip of the refill back into the barrel without affecting the stability of the knock or causing rattling. (You may have to experiment a bit, depending on the refill you’re working with.)

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Note that the tip of this Jetstream SXR refill is slightly too long when the pen is retracted. You can fix this problem by unscrewing the knock one, maybe two, turns to reach your preferred length. I have not found that unscrewing the knock in this way affects the usability of the pen.

Option 3: Ohto “Flash Dry” .5mm Needle-Tip Gel Refill

The third option I plan to discuss requires the most work, though it’s still a pretty easy hack. The Ohto “Flash Dry” refill has garnered a well-deserved reputation as an excellent, relatively fast-drying needle-tip gel option that is compatible with Parker-style ballpoint pens. The problem? It’s too long to fit the standard 849 ballpoint without modification. While you might be able to adjust the refill length using the trick described above (unscrewing the knock), you can also modify the refill by shaving off a bit of the clear plastic tubing using a craft knife or sharp scissors. GO SLOWLY. You only need to shave off .5-1mm, but if you take off too much you can add back length by wrapping a small piece of washi tape around the end of the cartridge. (This one will likely take some experimentation).

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The unmodified Ohto Flash-Dry refill (left)

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To reduce the length of the refill, pull off the black plastic cap and cut a small sliver off the clear refill tubing. Replace the black plastic cap and the refill should work. If you find that you cut too much (i.e., the tip doesn’t extend all the way through the opening when the knock is depressed), simply wrap a small piece of washi tape around the end of the refill to add back length.

Note that if you don’t want to mess around with hacking the Ohto Flash Dry refill to fit in the Caran d’Ache 849 ballpoint, this refill fits the 849 Rollerball without modification, and also has it’s own Ohto Fast-Dry click-pen, which is inexpensive and which we stock in the shop.

Again, I have to emphasize that although The Gentleman Stationer is an authorized Caran d’Ache retailer, hacks like these are NOT authorized and we obviously can’t guarantee that any modifications will work in all pens, due to slight variations in refill size (and even the various editions of the 849). Proceed at your own (admittedly low) risk, and have fun making your pens work for you!

Essential Office Supplies: Monteverde for Montblanc Refills

I had a long week at the day job: multiple depositions (via Zoom), which meant a lot of fast-paced, late night prep and rapid note-taking on whatever paper was in front of me at the time. Frankly I couldn’t be bothered with thinking about things like filling fountain pens, or even making sure I had paper good enough to use with a rollerball so I defaulted to this.

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A few years ago I reviewed the Monteverde Capless Gel Refill for the Montblanc Classique ballpoint, a pen that many of us have received as a gift over the years to commemorate big events such as graduations or promotions. While I appreciate a good ballpoint refill, the standard Montblanc insert isn’t a favorite. Monteverde, however, makes a capless gel refill that fits Montblanc ballpoints, and it’s available in a fine tip that writes an approximately .5mm line. Every once in a while I like to do a brief follow-up to see whether my opinions of a product have changed over time, and since I’ve used this pen exclusively for the past several days, now seems like a good time to check in.

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In short, I still love this refill for what it is. At roughly $13 for a pack of six (ordered directly from Monteverde), this Monteverde capless gel refill is an inexpensive, serviceable writer that turns an ok pen into a good one. Are these the best refills in the world? No. They can be slightly scratchy, and occasionally you’ll receive one that skips. But for what I need in an everyday office gel pen? They work just fine, and the availability of a blue-black color option isn’t something you see very often.

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Monteverde for Montblanc capless gel refills come in black, blue, and blue/black ink. I’ve not noticed this before, but Monteverde also states that these refills fit Sailor ballpoint pens, which may finally prompt me to pick up a Sailor Imperial Black ballpoint and complete my set.

Disclaimer: I purchased the refills featured in this review with my own funds, for my own personal use. This post does not contain affiliate links.

Rollin' in it: Two of My Favorite Rollerball Refills That Aren't the Schmidt P8126/P8127

If you've been paying regular attention to this blog and my social media feeds, you might have noticed that rollerball pens have been gradually working their way into my carry. Everyone talks about the Schmidt P8126/P8127 capless rollerball refill - and that refill is indeed one of the best out there for retractable pens. But what about other options for rollerball pens with caps? I'll walk you through two of my favorite refills here. 

Montblanc Rollerball pens will accept both a traditional rollerball refill as well as a fineliner refill. I tend to switch between them and they're both good (though expensive). 

In terms of overall quality and available color options, Montblanc makes my favorite rollerball refill. I've never had one dry out prematurely, the ink flow is consistent, and they're threaded, which eliminates any "tip wiggle" when used in authentic Montblanc pens. They also come in a wide range of colors, including not only black and blue, but red, green, turquoise, brown, and purple, in addition to periodic limited edition colors.  The downside? As you might expect, price, which can run upwards of $7 per refill, depending on where you shop.  

The Montblanc Le Petit Prince Classique Rollerball, courtesy of site sponsor Appelboom. Look for a full review in the future! This has the "bold" fineliner refill inserted. I've found that Montblanc refills tend to write a finer line than other brands - note the writing sample above comparing the Montblanc "medium" tip to the Schneider Topball 850 .5mm. 

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For a more economical take, my go-to option is the Schneider Topball 850, another quality German refill that I first discovered when I purchased the Field Notes "Brands Hall" rollerball pen a couple years back. It's possible to find these in a 10-pack at around $1-2 per refill, which is exceptional value, and the best part is that the Topball 850 comes in a .5mm tip size. I currently have this refill loaded into an Aurora Optima rollerball, a Karas Kustoms Reaktor Galaxie, and even an Inventery Bolt Action Pen (though I'm not sure how long it will last, given that it's not technically a "capless" cartridge - so far, so good though). Size-wise, the Topball 850 seems to be compatible with most pens that take a Pilot G2-size refill, though note that it is NOT compatible with Montblanc pens, and I've not yet had the chance to experiment and find a less-expensive Montblanc refill option. It does appear that Monteverde makes a refill advertised as compatible with Montblanc pens, though I've not tried it so YMMV. 

Takeaways and Where to Buy

Rollerball pens can serve as a much more functional writing instrument than fountain pens or even ballpoints, especially in a work environment.  The main downside is that refills can get relatively expensive, especially on pricier cartridges like Montblanc. For general writing, I use the Schneider Topball 850 (purchased from Amazon) in most of my pens, which is quite economical when purchased in packs of ten. Colors options are limited to black and blue, though. 

Montblanc rollerball refills are still among the best I've used over the years, and their "fineliner" option is exceptional. Montblanc cartridges are available from any authorized Montblanc retailer, but as I mentioned, they are quite pricey. I tend to bargain-hunt and stock up whenever I find a good deal, and Amazon is usually the easiest way to do that. As discussed above, if you can live with a "medium" tip size, Montblanc offers a selection of colors you can't find elsewhere in a rollerball. Note that Montblanc also releases rollerball versions of certain limited edition inks, such as Le Petit Prince, Lucky Orange, UNICEF Blue, and Writers' Edition inks such as Homer and Antoine de Saint-Exupery. These can be hard to find but do turn up if you look around or purchase directly from Montblanc.  

Disclaimer: This post contains affiliate links.