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

February 8, 2025

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.

Low Viscosity Ballpoint Writing Samples — 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.

Low Viscosity Ink Writing Sample Pens — 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.

Jetstream Edge .28mm and .38mm Refill — .38mm (left) vs. .28mm (right) Uniball Jetstream Edge

When Does "Fine" Become "Too Fine"? Finding the Sweet Spot for Extra-Fine Pens

August 16, 2023

I have relatively small handwriting, though I’m something of a special case since I tend to change my handwriting depending on what exactly it is that I’m working on. For standard writing and journaling, I’ll adopt a larger hand for which a medium nib is more suitable, but as I’ve mentioned before, a large portion of the writing that I do involves marking up and annotating documents that can contain very fine print. For work like this, I’ll typically need at least an extra-fine nib fountain pen, though this is where I tend to incorporate fine tip gel pens and ballpoints into my workflow.

Extra-Fine Writing Lineup: Ballpoints on a Table — My fine writing lineup, from left: Uniball Jetstream 4+1 Multi Pen, Anterique Brass .5mm Ballpoint, Uniball Jetstream “Tokyo Bike” 4+1 limited edition, two Jetstream Edge ballpoints in .38mm and .28mm, Uniball Jetstream 3 Multipen in .38mm tip size, Pilot Hi-Tec-C Coleto Multi Pen, and the Pilot Custom Heritage 912 with a PO Nib.

How fine can I go? Pretty Fine, But There Are Practical Limits.

On the fountain pen side of things, it’s difficult to get a nib that writes as fine as most .28mm or .38mm gel or ballpoint pens. Even if you’re using the Pilot PO (“Posting”) nib, Platinum’s UEF (Ultra Extra-fine), or a Saibi Togi-style nib, water-based fountain pen ink tends to spread on paper, so unless the pen writes fairly dry or you select a drier ink, you may have trouble obtaining the desired line width. For this reason, most of my annotation work is done with a finer gel pen or, more recently, low-viscosity ballpoint pens. I get a lot of questions about the best pen for “fine writing,” so I thought it might be interesting to talk a bit about the different options I rotate through on a regular basis and what my preferences are:

PIlot PO Nib writing sample — The Pilot PO nib leaves a line that’s roughly equivalent to a .38mm gel or ballpoint, provided you use good paper like the Midori MD pad pictured here.

Fountain Pens. My all-time preferred option for is the Pilot PO (“Posting”) nib, originally intended for addressing mail. It’s a VERY fine, slightly downturned nib that’s relatively dry and, when paired with an ink like standard Pilot Blue-Black, holds a fine line pretty well as long as you are using decent paper. On cheap office paper, however, even this ink tends to spread, which costs you the benefit of the finer point, which is why at the office I always have a gel or ballpoint pen with me.
Gel Pens. I rarely go finer than a .4mm Pilot Hi-Tec-C refill, since below that tip size I tend to run into drying/skipping/clogging issues, plus the writing experience becomes scratchy. My pen of choice is the Pilot Hi-Tec-C Coleto multi pen, which allows me to carry up to four different colors in a single pen body (or three plus a mechanical pencil). Lately, I’ve also added the .4mm Pilot Frixion to the rotation, and have been pleasantly surprised with how well it’s performed. The ink isn’t as dark as other gel pens, but it’s better than it used to be, and I plan to write up a full review of the Frixion once I’ve had more longer-term experience with it.
Ballpoint Pens. Honestly, where I’ve been spending most of my “fine-writing” time these days is in the hybrid/low-viscosity ballpoint category, since I generally find the writing experience smoother and more reliable, even if you go down to the .38mm tip size. I recently posted about my trip to New York City, where I visited Kinokuniya books and picked up a fistful of Uniball Jetstream multi pens, including a .38mm version that I had never seen before. While some claim to have experienced skipping and scratchy writing with the .38mm Jetstream cartridge, I’ve used this pen for years and never had an issue. That said, there’s no denying that a .5mm low-viscosity ballpoint refill is smoother, and unless I need to write really small, my pen of choice is the .5mm Uniball Jetstream (typically loaded into a multi pen) or the one of the .5mm Anterique “Mach Ball” pens.

The Anterique Mach Ball .5mm writes something more akin to a .4mm line - it’s narrower than the Jetstream .5mm despite having the same nominal tip size.

But What's the Absolute Finest I Can Go?

I used to say .38mm, but last month at Kinokuniya I picked up the .28mm Jetstream “Edge”, which features a Rotring-style hexagonal barrel and rounded grip section that some might find more comfortable than your typical technical pen. Check out the difference in tip size from the writing sample below:

Uniball Jetstream Tip Sizes — Comparing the range of Jetstream tip sizes.

The shocking thing to me is that even at .28mm, you don’t lose that much smoothness or visibility compared to the .38mm. That said, I’m not sure that the .28mm gives you meaningfully more versatility than a .38mm refill for actual writing, as opposed to technical drawing or art where the subtle differences between line widths actually make a difference. Even if the .28mm is usable (which it is!), I’m not sure that there’s a benefit beyond novelty for most people. .28mm probably sets the floor for me personally!

The Gentleman Stationer is supported entirely by purchases from the T.G.S. Curated Shop and pledges via the T.G.S. Patreon Program. This post does not contain paid advertising or third-party affiliate links.

Uniball Jetstream Multiple Tip Sizes Lined Paper

Three Ways to Use Uniball Jetstream Refills to Upgrade Pens for Work and School

August 2, 2023

I say this every year, but the end of the Summer vacation and travel season seems to come earlier every year. For our family, school starts Monday, and based on order patterns and inquiries I’ve been receiving through the blog, readers have begun winding down their Summer travel adventures and preparing to head back to the office, more often than not in-person. In the past, I’ve used this time of year to talk about some of my favorite everyday working stationery, which includes the beloved Uniball Jetstream - one of the best all-around pens (and refills!) on the market. Today, the goal is to take the opportunity to discuss how you can use the Jetstream to “upgrade” pens you may already own.

Many popular non-fountain pens on the market today ship with the Schmidt P8126-27 capless rollerball refill. (For those unfamiliar with the technical name, this is the same refill included with the Retro 51 Tornado and Baron Fig Squire. The P8127 is the medium-tip version, whereas the P8126 is a touch finer.) While this refill is probably the best capless rollerball refill available, I personally dislike it. Rollerballs in general are far more finicky for me to use than fountain pens, and with the exception of a few specific cartridges I enjoy, I nearly always swap out the stock refill for a new option. My swap refill of choice for Schmidt capless rollerballs is the Parker-style Jetstream SXR, but you’re not limited to that format for the Jetstream writing experience. I kit out most of my multi pens with Jetstream D1 refills, and am always looking for other Jetstream (or Jetstream-like) low-viscosity cartridges to “upgrade” my non-fountain pens.

Craighill Kepler Pen in Vapor Black PVD-coated stainless steel — The Craighill Kepler pen: a recent discovery. Check out the unique D1 refill mechanism below.

Why I Love the Uniball Jetstream

It writes smoothly, dries quickly, and doesn’t bleed through paper. As a low viscosity “hybrid” ballpoint pen, Jetstream ink combines the smoothness of gel ink with the quick drying and permanence of a ballpoint. Uniball was one of the original manufacturers to introduce this type of pen, and the category (which includes other excellent options) has exploded in popularity in recent years.
The standard Jetstream pens are easy to find in most stores, and we’ve recently been able to source the Jetstream SXR-600 Parker-style refills from Japan. I’ll talk further below about my favorite ways to use these cartridges in non-Jetstream pens.
Across the board, Jetstream pens and cartridges last a long time and are relatively inexpensive. The SXR-600 cartridges can be found for roughly $7-8 per unit, and the D1 refill for even less than that. While that might seem high, due to the nature of ballpoint ink, these last for a very long time without drying out (as in, years), especially if you like your tip sizes in .5mm or narrower

Craighill Kepler Pen D1 Refill Nock Mechanism — The Craighill Kepler pen kitted out with a Uniball Jetstream D1 refill.

My Favorite Iterations of the Uniball Jetstream and HoW I use them

Uniball Jetstream D1 Refill. The Jetstream D1 refill shot the Lamy 2000 4 Color Ballpoint (Multi Pen) to the top of my non-fountain pen everyday carry. But lately, I’ve also discovered that this refill fits the Craighill Kepler Pen, which I previously had assumed was another retractable rollerball pen but actually uses a unique D1 mechanism. Available colors include black, blue, and red.
Jetstream SXR-600 Parker-Style Cartridge. I have this refill loaded into pens including the Retro 51 Tornado, the Baron Fig Squire, the Schon DSGN Classic Machine Pen v.2, and the Caran d’Ache 849 “Rollerball”. This cartridge features an absolutely massive ink capacity, and I have yet to experience one running dry, especially in the finer tip sizes. The drawback is that they apparently only come in black ink. Blue, red, and green, please!
The Uniball Jetstream 3&1 or 4&1 Multi Pen. While you can’t swap the refills into a different pen body - at least not to my knowledge - Uniball makes its own multi pens, and they’re excellent. I personally prefer the “&1” series, which indicates that a mechanical pencil is included as one of the functions. On my recent trip to Kinokuniya in NYC, I went a bit crazy and picked up a handful of these in some less common collaboration colors. I love that the Uniball multi pens often contain red and green Jetstream refill options.

Uniball Jetstream pens and Kuru-Toga Mechanical Pencils Laid Out on table

If there’s one piece of “advice” that I would want readers to take away from this post, it’s not to give up on a pen just because you don’t like the stock refill. Unless a brand (like Lamy) heavily invests in proprietary refill designs, you can often find other compatible cartridges that will fit your pen and might better match your writing style. For a refill compatibility resource, I generally refer people to this comprehensive post by my friend Ana over at The Well-Appointed Desk.

Note: I will be attending the D.C. Pen Show from Thursday, August 3 through Sunday, August 6. While orders will still ship within our typical 2-3 business day processing time, if you’d like something to arrive early next week, please get your orders in by 5:00pm U.S. Central Time today.

Pen Review: Uniball Jetstream Multi Pen

December 21, 2016

I've been on a bit of a multifunction pen kick recently, picking up a handful of multi pens as part of a larger project I'm working on comparing the different options currently available on the market. A good multi pen has become an integral part of my daily carry and my workflow, giving me access to different ink types and colors - and sometimes a mechanical pencil - in one pen body. As I've said before, the downside to multi pens in general is that the refills can run out quickly, increasing the long-term cost of your "efficient" purchase. The Uniball Jetstream multi pen, which I'll review today, is probably one of the more cost-effective options of the "higher-end" multi pen bodies.

Four colors of ink + a .5mm mechanical pencil.

Uniball's Jetstream pens are famous for their smooth, quick-drying hybrid ballpoint ink that doesn't smear, and Jetstream multi pen refills are no different. The model that I purchased features a .5mm mechanical pencil, plus four different ink colors: black, blue, red, and green. With the exception of the green, the inks all lay on dark and smooth. (Like many green ballpoint inks, I found the Jetstream green be a bit skippy and somewhat temperamental.)

As you can see, most of the colors write a nice, solid line, with the exception of the finicky green.

The one potential drawback for some people might be the size of the pen. I'd characterize the Jetstream multi pen as moderately large, and since it's a five-unit pen, this thing has some girth. Despite the bit of bulk, it's very comfortable to use due to good ergonomics and a light weight. I also found the soft grip section very comfortable.

.5mm vs .7mm

There is something of a debate with respect to .5mm vs .7mm in the Jetstream line. Many people don't like the .5mm and find it writes too thin and scratchy of a line. I've personally had nothing but good experiences with the .5mm, but the .7mm is excellent as well, so if you're on the fence I would go with the wider tip size. You can always swap the refills out later.

Takeaways/Where to Buy

I'm really enjoying the Jetstream multi pen, especially at work where I need a fine point for annotation and I sometimes have to deal with copy paper so thin that it's impossible to use with fountain pens. The ability to switch between different color inks on the fly, knowing that all of them will write reasonably well on nearly all paper, removes yet another thing from the "worry list" in the midst of a hectic workday.

In addition to the excellent writing experience it offers, the Uniball Jetstream is probably the most reasonably priced of the good multi pens out there on the market. Right now, you can find both the .5mm version and the .7mm version on the market in various iterations, including several special editions that Uni has been releasing such as the “Bamboo” version that we stock in our own shop. Individual color refills are also available separately. Note that the refills for this particular multi pen are proprietary, so you are limited to the four colors Uniball offers and won't be able to swap in refills from another brand (unless, of course, you figure out a way to hack the pen.)

For those of you who already use a multi pen that accepts D1 refills (like the Lamy 2000 4-color ballpoint), Jetpens also carries a Uniball Jetstream D1 refill, which is more expensive but makes for a nice writing experience.

Disclaimer: I purchased the pen featured in this review with my own funds for my personal collection.