Additive Pens Double Helix Fountain Pen Review

Additive Pens use 3D printing to produce unique looking pens. I’ve had this pen a couple of years now and so this is a long term review. The pens come with stainless steel Jowo nibs but I’ve been using mine with a 14k gold broad nib ground to a stub by FP Nibs.

Price: $180
Filling method: eye-dropper
Barrel options: Double Helix (this one); Ribbon; Inverse Ribbon
Nib options: Stainless steel #6 in extra-fine, fine, medium, broad, 1.1 stub, or 1.5 stub
Reviewed nib: FP Nibs 14k rhodium-plated broad stub (approximately €135)

Additive Pens consists of Jerry Tang, who on finding a stash of his parents’ old fountain pens when he was middle school, became fascinated with the mechanics of them, and Andrzej Tunkiel, the engineer who came up with the original design for the Double Helix pen.

When I bought my pen they were being released in small batches via Instagram and they came with a choice of section and cap acrylics. I went for this Jonathan Brooks Dark Cherry Koi pattern because I was fairly sure it would be the only way I’d be able to own anything made by Mr Brooks. Currently, as Additive Pens catch up with backorders, this kind of option isn’t available and the pens all come with clear sections and caps. That’s not necessarily all bad as the clear caps and sections create a consistent appearance and look pretty good – maybe even better than the solid acrylic. That said, the pattern in the Dark Cherry Koi acrylic is complex, unusual and beautiful and I would love a whole pen made from it. (But not a Double Helix, obviously, as you wouldn’t be able to see the insides.)

The Double Helix is a big pen. It’s so long it fits a little uncomfortably into many pen cases. It’s light, though, and has a nice long section that keeps the threads from your delicate fingertips. This all makes for a pen that’s comfortable to hold and use for long periods.

The cap screws closed and doesn’t post. It looks fabulous in this acrylic. Since I bought this pen the cap has been redesigned. It now has an internal step to provide, I assume, a seal to help prevent the nib drying out, as well as a breather hole, and a machined finial that will provide for a clip option in the future. I can’t comment on any of this, unfortunately. All I can vouch for is the quality of the fit and finish of the cap I have, which is excellent.

The pen is, of course, an eye-dropper. It’s easily filled using a syringe or, if you’re feeling brave, pouring from a small Diamine bottle or a sample bottle. The ink flows down the two helixes and looks fantastic.

It can be a little hard to get going after filling. The usual eye-dropper trick of fearlessly turning the pen back upright when the barrel is mostly screwed back on isn’t so effective here. You can either turn the pen early and get ink spreading down the section threads or you can leave it too late to force the ink into the feed. The only sensible thing to do is to fill the pen, screw the section back in, then rest the pen nib down (cap on!) and wait patiently. You could use this time to admire the beauty of the ink in the helixes and contemplate the miracle of DNA.

There are o-rings at each end of the section that reduce the need for silicon gel to form a seal. However I still use a bit to be on the safe side. A little ink does leak onto the threads if you aren’t careful but I’ve never had an issue with it leaking out from the pen itself.

It’s virtually impossible to clean the pen completely. Part of this is the design because you can’t effectively shake water inside the tubes and part of it is the material use because ink likes to cling to it. This latter issue has apparently been addressed with the use of a different plastic in newer models. I don’t know how effective that is but, really, it doesn’t matter. There is only the barest trace of ink left clinging to the insides of the helixes and as soon as you refill then pen it disappears. The new ink isn’t discoloured in the slightest and the pen glories in the new colour. There was a time when I was extremely particular about getting my pens completely clean and if I was still that way this would have bothered me a lot, so I completely understand if this would be an issue for you.

By default Additive Pens supply stainless steel #6 Jowo nibs. I’ve found Jowo nibs to be extremely reliable and good smooth writers. I bought mine with a broad nib and it was perfectly okay but what’s also great about Jowo nibs is how commonly used they are, which makes swapping them from pen to pen a doddle. (Franklin-Christoph and Edison Pens use Jowo nibs, as well as many custom pen makers.) I invested in a selection of 14k gold #6 Jowo nibs and the one currently in this pen is a broad stub I bought from FP Nibs. FP Nibs offer a huge range of grinds on a wide variety of nibs. This nib is lovely and smooth, with the line variation you’d expect from a broad stub. The feed keeps it supplied with a good amount of ink. The pen does experience the occasional hard start but I think that’s perhaps due to some drying out when capped, which may have been solved by the new design. (I had expected some flow issues because of the helix design perhaps not being conducive to getting the ink along the length of the pen to the feed but this doesn’t seem to be a problem at all.)

The Double Helix is an interesting pen because of its unique design. It’s a step above the usual clear-barrelled eye-dropper because the helixes are not only unusual in themselves, they transform the way the ink affects the appearance of the pen. It really is fun and different. It’s a comfortable pen to hold because of it’s large but light. Even with the standard steel nib the writing experience is great. All that lets it down is the material used to make the barrel, which feels a little cheap and which clings onto the ink when cleaning. For me, these are minor issues and they may well have been resolved (or at the very least reduced) by the new material used.

I’d love to see more pens being made by 3D printing but Jerry Tang told me how costly the process is, which makes it extremely difficult to turn 3D pen making into a full-time business. Right now, Jerry and Andrjez are able to run Additive Pens as a side project. They do have plans for new designs and more collaborations, though, and I’m looking forward to seeing what they have up their sleeves in the future.

I bought this pen with my own hard-earned money and these views are all my very own. I contacted Jerry Tang for additional information.

3 Comments

  1. You neglected to mention one very irritating design flaw. Both the cap and section unscrew in the same direction. This means if you accidentally tighten the cap too much you unscrew the section when taking the cap off. This could have been corrected by making the threads in opposite directions like the HEXPEN. Also, they have marginal customer service. I attempted to contact them several times after purchasing a couple of there pens from another owner and never received a response.

    Overall, my experience with HEXPEN has been superior in every aspect.

    But, all that said they are beautiful pens and I enjoy using mine.

    1. I must admit I hadn’t noticed the cap and section unscrewing in the same direction. I think on mine the o-ring is perhaps grippy enough for it not to be an issue. I can see how it could become a problem over time though.

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