I'm prepared to eat my words on the Vac Mini. After a less-than-stellar experience with the Vac 700, the idea of a miniature version of TWSBI's vacuum filler didn't excite me in the least, and I dropped one in my Amazon shopping cart as an afterthought when I was stocking up on something else. I fully expected this to be a "review purchase," after which I'd resell the pen. I was wrong, and I'm pleasantly surprised by TWSBI's latest "mini" model.
A Recap of the Vac 700 and "Vacuum Fillers"
In 2012, TWSBI introduced the Vac 700, which at $70 was the most reasonably priced "Vacuum Filler" fountain pen available on the market. The vacuum filling system is cool. The technical niceties are better explained elsewhere, but in short you stick the nib into an ink bottle, depress a plunger rod, and at the end of the downstroke the negative pressure causes the barrel of the pen to fill with ink. The Vac 700 was admired for bringing a unique filling system to the masses at a favorable price point, but has been criticized over the years for its somewhat clunky aesthetics and early quality control problems with the nibs. I eventually sold mine after a couple of months, and haven't been tempted by another vacuum filler other than Pilot's higher-end Custom 823 (which is still on "The List"). [2021 Update: TWSBI has released a new version of the Vac 700, dubbed the Vac700R, which adjusted the filling system and valve to increase ink flow and solves many of the early problems I and others had with the pen. It’s definitely worth checking out, though the Vac Mini probably remains my favorite due to the pocketable format.]
Note: A "vacuum filling" fountain pen is not the same thing as a "vacumatic" fountain pen. Despite the similar sounding names, a "vacumatic" filling fountain pen uses a pump. I am working on my own video demonstrating these filling systems, and will supplement this review at some point in the future. For now, please check out Brian Goulet's video here on how to fill a vacuum-fill fountain pen.
The Build of the Vac Mini
The Vac Mini is not just a slimmed down version of the Vac 700: it's an entirely new design, and a good one at that. The Vac Mini has none of the clunky, mismatched styling that I disliked so much with its larger sibling (err, cousin?). It's much smaller, and works well as a pocket carry option for those days when you plan to be on the move and don't want to carry a full bag or pen case, but still have some serious writing to do and need a pen with a large ink capacity.
A shot of the Vac Mini's streamlined aesthetics. Note the slight, yet noticeable, "step" from the barrel to the nib section.
The design reminds me more of the Diamond Mini than the Vac 700, though the Vac Mini is more streamlined and foregoes the sharp facets of the Diamond 580 line (which probably lowers the risk of the plastic cracking). There is a noticeable "step" from the barrel to the nib section (see picture above), and depending on how/where on the section you grip your pen, this could range from being a non-issue to a deal-breaker. Similarly, this pen is not one that you can use unposted for long periods of time, though for short jottings I've found that it works fine.
The TWSBI Vac Mini unposted. I've found that it works fine for short notes.
Which brings me to a second commonly heard criticism of the Vac Mini: to post the pen, you have to screw the cap onto the threaded end of the pen (the "end cap"). Some users have complained that this process takes too long, and makes this "pocket pen" too inconvenient to carry if you're someone who constantly caps/uncaps/posts/unposts the pen to take notes in short bursts. As I noted above, I've not had too much trouble in this regard, since I find the Vac Mini fine to write with unposted for brief periods of note-taking.
Many people will also have to pay attention to the orientation of the clip when you post the cap. The end cap is double-threaded, meaning that there's more than one way to screw on the cap, and as a result the clip can end up facing up or down. To some people, this means that the clip will end up "digging into your hand" or "not digging into your hand." My hands aren't large enough to make this an issue, but I can see how it could be extremely uncomfortable for some people. I've taken two pictures (below), attempting to demonstrate what people are complaining about:
At least on my pen, I've found that if you start threading the cap with the clip facing "down" (away from the top of the nib), you'll end up posting the pen with the clip facing away from your hand, and shouldn't have an issue with the clip bothering you as you write.
To ensure the cap posts "correctly", with the clip facing away from your hand, start threading the cap with the clip facing the feed, not the top of the nib. Annoying at first but pretty soon it becomes second nature.
The Nib
I purchased my pen with a medium nib. TWSBI's medium nibs are what I would call a "true medium"--not too fine, but also not too broad. This one is particularly smooth and wet, and one of the better TWSBI nibs that I've owned.
I've always liked TWSBI's nibs (now made by JoWo), and their logo engraved on the front. Unfortunately, I don't believe the Vac Mini nib units are interchangeable.
One thing to be sure to remember on a vacuum filler fountain pen: If you are writing for a long-ish period of time (as in, more than half a page), unscrew the end cap slightly. The metal rod that makes up the filler mechanism has a small O-ring at the end, which seals the nib and feed and prevents leaks when the end cap is closed all the way. It's a handy feature to have on a pen that holds this much ink, and makes this a good option for airplane travel, but you'll need to open the seal before writing to allow the ink to flow freely.
On the Vac Mini (and any vacuum-filling pen, for that matter) you should open the end-cap for longer writing sessions, to allow the ink to flow.
Takeaways
I purchased this pen a few weeks ago, and I love having it as a part of my carry. It's everything that I want in a pocket pen: it has a large ink capacity and writes reliably. I also prefer the more streamlined look of the Vac Mini to the sharp facets of the TWSBI Diamond 580 and the Diamond Mini. At its price point ($60), this pen will get a lot of use from me. In my opinion, TWSBI generally represents excellent value regardless of your level of experience with fountain pens. As of 2021, you can now purchase the TWSBI Vac Mini directly from T.G.S. via The Curated Shop.
I am not, however, going to add the Vac Mini to my list of Top Fountain Pens under $75. Why not? Risk of new user confusion. I think the filling system and the mechanism for posting the cap are too complex for most users to want to bother with. I'm a pen geek, and things like screw-on caps and vacuum filling systems are fun for me to play with. The average user, or someone looking to buy their first fountain pen, probably should not buy this pen over a cartridge/converter pen or a piston filler. The filling mechanism is more complex, and between having to unscrew the end cap for longer writing sessions, threading the cap to post, and paying attention to how the clip is oriented to prevent discomfort, that's a lot for a new user to have to deal with. If you are just getting into fountain pens, the TWSBI Eco is probably the better buy for a fountain pen newbie, at half the price.
AND....it wouldn't be a TWSBI without the famous red logo on the top of the cap!
Further Reading
On the whole, the reaction to the Vac Mini has been positive. As I mentioned above, however, some people have found the Vac Mini too difficult to post/unpost quickly, making it less unusable for them as a pocket carry. Check out Matthew's review over at Nib & Ink for this perspective. Azizah over at Gourmet Pens liked the pen, on the whole, but wasn't crazy about the aesthetics of the pen and thought her broad nib was on the dry side.
DISCLAIMER: I purchased this pen with my own money, for my own collection. In the years since this post was originally published I have opened the T.G.S. Curated Shop (which is an authorized retailer of TWSBI and certain other select brands) and the T.G.S. Patreon Program, both of which allow me to support the site directly. All levels of support are greatly appreciated (but far from obligatory - my content here is free)!