I don’t know precisely why I love my TWSBIs as much as I do. Sure there’s the fact that they’re sort of modern, tech-y looking with the see through barrels, and the piston filler. There’s the fact that my TWSBIs almost always start on the first go, and don’t run dry unless they are literally out of ink. The, ECOs, of which I have three, are incredibly reasonably priced so they make great entry-level fountain pens. They provide a nice, if not exceptional, writing experience. They’re available in a ton of different nib sizes. Ok… I guess I’ve given myself a few reasons.

Despite really liking my TWSBI ECOs, I’ve never actually branched out and tried any of their other pens. (I take that back, I tried the TWSBI Swipe a while ago and thought it was ok.) But this time I saw the TWSBI Diamond Mini AL in Grape (a limited edition color!; $62.50) and decided to give the more expensive model a go!


The Diamond Mini AL is TWSBI’s version of a pocket pen. It is styled similarly to the other pens, in the sense that it has a transparent plastic barrel which gives you a bird’s eye view of the piston filling system. There are differences though. The grip and part of the piston system are designed in aluminum. The barrel of the pen is faceted (hence the “Diamond” feel and look). While the ECO and the SWIPE tend to be boxier, with edges on the cap, the Diamond Mini’s edges are rounded, and the cap is tapered. Overall while the ECO is utilitarian, the Diamond Mini is a bit sleeker looking.
I decided to compare a few pens that I use as daily writers to give you a sense of size.


L to R: TWSBI Eco, TWSBI Diamond Mini AL, Kaweco AL Sport, Sailor Pro-Gear Slim.
While the pens vary quite a bit in length when capped, when uncapped the Diamond Mini AL and the Kaweco AL Sport aren’t that different in length. The nibs, however, do have a size differential. In terms of weight they’re very similar: The Pro Gear comes in at 19gm, the ECO at 20, the AL Sport at 21g, and finally the Diamond Mini AL is the heaviest at 23g. But that’s not a HUGE range.

So what do I think? If I’m entirely 100% honest, I don’t feel much of a writing difference between the ECO and the Diamond Mini AL. This is my first extra fine nib from TWSBI, and given that TWSBI tends to use western-style nibs, I don’t find the extra fine to be scratchy in the least. In fact I quite like it. The pen is a bit weightier in my hand, and it’s smaller in size, but I have small hands and it seems like a comfortable writer. So what would make me pay more for the Diamond AL Mini? To me, it comes down to aesthetics. The Mini is fun, and often I do prefer aluminum to plastic (see my preferences for Kawecos!), but given that I don’t see a huge writing difference, I feel like I’m more apt to stick with the ECOs than amass another collection.
Do you have a favorite TWSBI? I’d love to hear about it!
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