Hands-on with the TWSBI Diamond Mini Fountain Pen

WHAT YOU NEED TO KNOW
Brand	TWSBI
Model	Mini Classic
Nib Material	Steel
Nib Sizes	EF,F,M,B
Filling System	Piston
Dimensions	Capped Length: 117.5mm / 4.6″ Posted Length: 140mm / 5.5″ Uncapped Length: 108mm / 4.25″ Barrel Diameter: 13mm / .51″ Section Diameter: 9.7-11.3mm / .38-.44″
Weight	21g / 0.74oz
Notes	Available in 3 styles: Classic, Black, and Clear
Price	$50
Availability	Now

The TWSBI Mini, it’s finally here! It feels like we’ve waited ages for this pen to arrive. We first reported on it just over a year ago and in December we announced an estimated release date of June 2012 on our TWSBI Timeline. Since that time the Mini has stayed under the radar, only surfacing to show off possible color options. On October 22nd they officially went on sale in three styles: an all clear demo, solid black with chrome trim, and the Classic, which combines a clear barrel with a black cap, section, and piston knob.

Being in the Diamond family, it’s not surprising that the Mini looks like a shrunken down 540. There are a couple slight differences in the Mini that I actually wouldn’t mind seeing on the 540. The biggest change, and a vital one for the Mini, is the addition of threads to the rear of the barrel for posting the cap. The other is the style of the cap band. I’m glad TWSBI didn’t just transfer the 540′s over the Mini as that would have looked odd. In addition to those two changes there’s also the addition of a metal accent at the front of the section and the seals on the piston of the Mini look ever so slightly thicker than on my 540.

The Classic called out to me the most and I sincerely hope TWSBI offers the 540 in this style. Even though the changes to the Mini were few and subtle, I think it looks much cleaner than the 540. The revised cap band definitely contributes to this new clean look, but I think most of it comes from the mixing of opaque black and clear parts. The black piston knob, section, and cap cover up the bits we’re used to seeing, creating a semi-professional look while the clear barrel reveals the piston, adding some uniqueness and intrigue to what would be an otherwise boring pen (glances at the all black Mini). The only issue I have with the Mini is the o-ring on the rear of the barrel. It’s a useful feature and I’m glad it’s there, but it detracts from the pleasing lines of the pen.

Owning a TWSBI that was designed to be posted is like a dream come true. The cap locks down securely in just more than one full revolution and engages the o-ring for the last half a turn. As long as the cap is touching the o-ring it’ll stay in place. That half a turn also gives you enough play that you should easily be able to find a spot where the clip lines up with the nib. That’s important because when the cap is fully locked down it doesn’t line up with the nib. Some of you may not care about that, but for me it’s one of the most important aspects of a pen. So, while the o-ring may not be the most beautiful part of the pen, it is certainly one of the most useful.

The TWSBI Diamond Mini is a convenient and comfortable pen. I think it offers the best of worlds. The most likely competitor to the Mini is probably the Kaweco Sport. While the Kaweco is much lighter and more compact, it’s not nearly as comfortable to use. It’s also not a piston filler. But, it is half the price and has lots of nibs that are easily swappable, readily available, and cheaper than nibs for the 540 (note: the 540 section won’t swap directly onto the Mini, but the nib/feed unit will). To determine which pen is for you really depends on how light and compact you need your pen to be. For my use, which only requires a pen to be compact enough to hide in a shirt pocket, the Mini is perfect.

The piston unit in the Mini is solid. The dual seals are thick and beefy and should last a lifetime. The piston is well designed in that it fully retracts, butting up against the unit housing so that as much of the barrel can be filled as possible. I did run into a bit of an odd feeling while operating the piston. On both of my Minis I noticed that the action wasn’t completely smooth. There are three points during the extending/retracting cycle where it feels like the piston knob is settling into place, like there’s detents along the shaft. I don’t know if this is found on every Mini or just mine. I’m guessing this will smooth out with use. It’s just odd because I never noticed it on any of my 530/540′s.

I’m happy to share that the Mini is fully compatible with the Diamond Ink bottle. Filling is quick, simple, and clean and it all but guarantees a 100% fill.

Daily use of the Mini has been quite pleasant. It nestles nicely into my shirt pocket and is light enough that most times I forget it’s there. When it’s needed, the pen can be used to make quick notes without posting, something the Kaweco Sport couldn’t do, at least not without being annoyingly awkward. For more extended writing sessions the Mini is just large enough to be comfortable, that is until things start stretching into 3-4 pages. When the writing is done the Mini easily clips back into my shirt pocket with one hand.

I received a fine and a broad nib in my pens and they both performed wonderfully out of the box. I hate to say this, but I was actually surprised by how well they wrote given TWSBI’s history. Both nibs were smooth and the flow in the broad nib was slightly wet while the flow in the fine nib was spot on in the middle of the range. Hopefully, this is a sign of things to come. But if it’s not, I wouldn’t use it as an excuse to not buy a pen. If you like it, buy it, and if the nib is bad then send it to a nib meister to be perfected. It’s worth it.

TWSBI has done a lot of things right with the Mini. It’s an excellent fountain pen regardless of size or price. It’s very easily user serviceable and comes with excellent customer service. There are a few other options out there that do the whole compact thing better than the Mini, but none that are as well rounded.