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Vintage Living in the Modern World.
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Should You Buy a "Bulkfiller"? Checking in on one of the Internet's Most Talked About Filling Systems

September 4, 2024

I’ve avoided writing about the “Conid craze” that took over the pen community during the Pandemic years. While I have nothing against these pens - I currently own a Conid Bulkfiller Kingsize that I regularly use, and previously reviewed the Bulkfiller Minimalistica - the prices these pens were commanding on the secondary market (in the multiple thousands of dollars) struck me as extreme. Today, it’s died down a bit as Conid has resumed limited production, and more companies are releasing pens with a version of the “Conid filling system”, which Conid calls the “Bulkfiller” but which has alternately been described as a syringe filler, or “pump piston” (Kyuseido’s term). While I might eventually write longer form reviews of all of these specific pens, each of which offer a slightly different take on the technology, I wanted to start with my general thoughts on the filling system itself, including what I view as its advantages and disadvantages, as well as alternatives that some might find less finicky.

The Conid Bulkfiller Kingsize with the plunger rod engaged and extended, ready to fill.

How Does a Syringe Filling System Work?

I prefer describing this filling system as a “syringe filler” because I find it a more intuitive description of how these pens work. (Yes, I know these are distinct from various vintage filling mechanisms marketed as “syringe fillers.” This article is about the modern category of pens, and I may be using my own terminology here.) These pens use a plunger, much like a vacuum-filling pen, but while a typical vacuum-filler takes advantage of a vacuum in the barrel created when the user depresses the plunger past a certain point, a syringe-filler fills on the upstroke (like a syringe). The filling mechanism is somewhat complex, with a more involved filling process compared to most other fountain pens:

  • You start by unscrewing the blind cap, which disengages the plunger rod just as you would with a vacuum-filler.

  • You then pull the rod all the way back, and thread or hook the seal into the plunger head, which sits at the back of the barrel. This will allow you to push the newly assembled “plunger” all the way forward and prepare to take up ink.

  • Dip the nib/section of the pen into the ink bottle, and then slowly draw back on the plunger (like a syringe), which should allow you to fill the barrel to near 100% capacity. At the top of the filling stroke, you unscrew the rod to disengage the plunger rod from the seal and slide it back into position at the top of the section.

Check out this YouTube video from Doodlebud, which is an excellent demonstration of how the Conid version of this filling system works.

Freshly inked with 3 Oysters Doldam, a great blue-grey!

What I View as the Advantages of This Filling System

As I mentioned, this type of filling system is more complex, necessitating a more involved process to fill your fountain pen. So why should you bother, apart from the inherent “cool factor” of having such an overengineered mechanism on an already overengineered category of writing instruments?

  • Ink Capacity. These pens hold an insane amount of ink (anywhere from 2-4ml, depending on the model). For those obsessed with maximizing ink capacity and using the full barrel as an ink reservoir, syringe fillers and eyedroppers are your best options. If you don’t change ink often, and want to refill as infrequently as possible while not messing around with inherently messy eyedroppers, you definitely want to consider this filling system.

  • Ease of Cleaning. Because you can force a large volume of water through the pen using the high-capacity filling mechanism, these pens are easier to clean than vacuum-fillers, standard piston fillers, eyedroppers, and honestly pretty much any other pen. My Conid Kingsize demonstrator will flush clean in as little as one or two cycles.

  • Travel-Friendliness. When the blind cap is fully secured and the plunger rod completely screwed down, it creates a seal between the main ink reservoir (the barrel) and the primary writing reservoir in the section, which will help prevent burping and leaks during air travel and temperature fluctuations. So not only do you have a pen that will hold an extraordinary amount of ink for an extended trip, but you have the same safeguards against “inksplosions” as a vacuum-filler or Japanese-style eyedropper system. On all of these pens, you will need to open the valve to allow ink to flow freely for a more extended writing session.

  • Ink Flow. With the valve open, you can get pretty heavy inkflow due to the volume of ink in the barrel. If you enjoy wet writers, or have a broader nib or ebonite feed that uses a lot of ink, you may love this pen. That said, as I’ll discuss further below, the ink doesn’t always flow seamlessly between the two reservoirs. You sometimes have to shake/tap the pen to force additional ink from the barrel into the section, which can cause significant variations in the level of ink flowing through the nib and feed that leads to the pen writing an inconsistent line.

The Kyusedio Kakari and Conid Bulkfiller Kingsize, both inked but not “full”. (I’ve been writing with both for a couple of weeks and look at all the ink that’s still in the pen!

The Disadvantages

  • Price. Conid ran into production issues over the past several years, leading to a scarcity which pushed demand far in excess of what the company can produce, with prices increasing accordingly. Currently, a Bulkfiller Kingsize starts at $900 for the pen, which I don’t believe includes the cost of the nib, shipping, and applicable taxes and customs duties. That is, if you can get one direct from Penworld, as these are sold in limited batches that often sell out in minutes, and secondary market prices have been astronomic at times. The Kyuseido Kakari is slightly less expensive for a 14k gold nib version. Companies such as Asvine and PenBBS make lower-cost versions of this filling system in the $50-60 dollar range, which feature steel nibs, so I would likely recommend starting here simply to see if you like the mechanism and design before acquiring a more expensive option.

  • Yes, the Mechanism Can Be Finicky. Because there are so many moving parts, more can go wrong. The most widespread problems I hear about with these pens, across brands, is the piston/plunger head “sticking” at the top of the barrel, and/or the plunger rod becoming stuck and not disengaging from the plunger. While these issues are more common in the lower-cost pens, I’ve had the issue occasionally arise with my Conids and Kyuseido pens as well. Thankfully, I’ve always been able to figure out a fix myself, because shipping pens internationally for a repair is not a simple (or inexpensive) proposition.

  • Inconsistent Inkflow. I’ve found the ink flow on my bulkfiller/syringe-filler fountain pens to be less consistent than with my vacuum-fillers and Japanese-style eyedroppers. On nearly every pen I have used with this style of filling system, the ink has a tendency to stick at the top of the first reservoir, which requires you to shake or tap the pen to get additional ink to flow from the barrel. I assume this is due to surface tension, but it’s somewhat frustrating on pens at this price point that someone hasn’t figured out how to fix the issue. Does it keep me from using these pens? No. But I’d be lying if I said it wasn’t annoying. Honestly, the issue was so bad on my original Minimalistica that I ended up parting with the pen. It’s somewhat better on my new Bulkfiller Kingsize and Kyuseido Kakari, but still a factor.

An approximation of what can happen with the ink “sticking” at the top of the reservoir and not flowing down. I tried to recreate the issue here for photography purposes, but it tends to happen spontaneously as you’re writing, requiring you to tap or shake the pen to get ink flowing again.

Closing THoughts, Alternatives for a Similar Experience, and a note on fomo

Are these cool pens, that feature a lot of clever engineering that’s enjoyable to use every day? Absolutely. Would I buy my pens again? Absolutely. Do I feel like the hype on these pens is somewhat excessive and that people should carefully consider their options before making such an expensive purchase? Also yes. As I noted in my original review of the Conid Minimalistica nearly a decade ago, these are “pen geek” pens, and I don’t recommend them to everyone, especially beginners. Be prepared to tinker a bit, and if you’re newer to fountain pens, I’d recommend trying one in person or experimenting with the lower cost options from PenBBS (Model 355) or Asvine before spending a lot of money. Honestly, try a Japanese-style eyedropper to see whether you even like a pen that holds this much ink. If you’re a serial ink-changer, you may find that you prefer cartridge-converter.

As you can see, because they hold so much ink, they tend to be larger pens. Shown here alongside a Montblanc 146 (far left) and Waterman Exception (far right).

The observations I make in this post apply across brands and models using this filling system, so there’s no “knock” intended on any particular pen. I enjoy using both my Conid Bulkfiller and Kyuseido Kakari, both are well-made, quality pens, and they are both going with me on vacation tomorrow. As a pen enthusiast and longtime fountain pen user, I love having examples of all the creativity and craftsmanship that goes into designing these pens.

So why have I been so conscious about emphasizing the “downsides” in addition to the positives? Because I’ve noticed a significant amount of social media-generated FOMO associated with these pens, which can be dangerous with such an expensive, often sight-unseen purchase. I don’t subscribe to the mentality I’ve seen in certain forums that acquiring one of these pens should automatically be everyone’s “grail,” and I cringe when I read about relative fountain pen newbies paying thousands for secondary market Conids before ever using one. As is the case with nearly any pen or filling system, these pens aren’t for everyone, and for ever person I know who considers their bulkfiller/syringe-filler a “grail pen,” I know someone else who finds these pens finicky and frustrating to use. To that end, if you want to use one of these pens to see if they’re for you, you’re always welcome to try mine. Pen show after-hours gatherings are great venues, as are local pen clubs, and since we now have a Gentleman Stationer physical store, just stop by! (Permanent hours will be posted next week.)

The Gentleman Stationer is supported by purchases from the T.G.S. Curated Shop and pledges via the T.G.S Patreon Program.

In Editorial Tags Bulkfiller, Syringe Filler, Filling Systems, Editorial
3 Comments
Platinum-Curidas-Converter.jpeg

Filling Systems: Pros and Cons of Piston Fillers, Vacuum Fillers, and Cartridge/Converter Fountain Pens

May 8, 2021

Vintage vs. modern, steel nib vs. gold nib, extra-fine vs. triple-broad, Safari vs. Al-Star: the fountain pen community has always had - and always will have - various “debates” over what’s better. Of course there’s no right answer, but endlessly discussing the minutiae is part of what makes this hobby interesting, and the community so much fun. (Well, 99% of the community, setting aside the 1% that tends to take everything far too seriously.)

When it comes to my own personal collecting, my interests focus on two areas: materials (mainly celluloid) and filling systems. Acquiring pens made from rare and/or vintage celluloids, which have a depth and warmth that modern acrylics and resins lack, caters to the aesthetic/artistic interest I have in pens. On the other hand, exploring different filling systems brings out the true pen nerd in me, and is probably the reason I have an ever-expanding, wildly diverse accumulation of fountain pens. When manufacturers keep experimenting with new methods to fill fountain pens, you can’t help but try them all!

The Pilot Custom 74 fountain pen, featuring Pilot’s proprietary Con-70 Converter. While I love this particular converter, Japanese companies such as Pilot and Platinum (shown at the top) all use their own converter design, so you will need to buy separate converters fore each brand of pen.

The Pilot Custom 74 fountain pen, featuring Pilot’s proprietary Con-70 Converter. While I love this particular converter, Japanese companies such as Pilot and Platinum (shown at the top) all use their own converter design, so you will need to buy separate converters fore each brand of pen.

Cartridge-Converter: The Best Filling System for Most People

People often ask me, what’s the best filling system for the everyday user? For the casual enthusiast, this answer is clear: Cartridge/converter offers a user-friendly, versatile mechanism that’s straightforward and especially appropriate for first-timers and those who travel a lot or otherwise need to be able to refill on the go. I enjoy many cartridge/converter fountain pens myself, and I certainly won’t pass on a pen that I otherwise find interesting or attractive simply because it’s not exclusively bottle-fill. Pros and cons of cartridge-converter filling systems include:

Pros:

  • Versatility. Cartridge/converter filling systems allow you to use ink cartridges and fill from an ink bottle. It’s not just about whether you’re a beginner - I’ve been in this hobby a decade or more, and still keep cartridge/converter fountain pens in rotation because they’re great for travel. (You can read more on why I like ink cartridges here.)

  • Ease of use. If you’re new to fountain pens and simply want to get to writing without worrying about making a mess learning to fill from a bottle, just pop in a cartridge and you’re on your way.

  • Easy to Clean. Cartridge/converter pens are also exceptionally easy to clean by flushing them out with an inexpensive bulb syringe, or soaking the nib unit in water or running it through an ultrasonic cleaner. If you enjoy using highly saturated or shimmer inks that might stain or otherwise be hard to clean out of a pen, cartridge/converter pens are typically the way to go.

Cons:

  • Small Ink Capacity. Both cartridges and converters generally hold less than 1ml of ink. On a busy day, I can easily write one or more cartridge/converter pens dry. If you enjoy changing inks frequently, you might view this as a “pro,” but high-volume writers looking to go a full day or more on a single fill might prefer something with a bigger ink capacity.

  • Proprietary Cartridges and Converters. While some pen companies have moved towards a universal, standard international converter that is freely interchangeable between different pens, many major brands (including Pilot, Platinum, Sailor, Lamy, and Parker, just to name a few) use proprietary cartridges and converters that only work in their pens. To add insult to injury, many pens don’t actually ship with a converter, so it creates an added expense when you can’t use one of the dozens of converters already in your desk drawer.

  • Limited Ink Selection. If you stick to cartridges, you won’t have as many ink options. Don’t get me wrong, you’ll still have plenty, as brands like Diamine, Herbin, Sailor, and Caran d’Ache release more of their ink lines in cartridge form, but you’ll likely be excluded from most of the boutique and specialty inks unless you buy the converter and fill from a bottle.

Many piston filling fountain pens are larger, to maximize ink capacity. The smaller pens, second from left and second from right, are cartridge converter, and the rest are piston-fill.

Many piston filling fountain pens are larger, to maximize ink capacity. The smaller pens, second from left and second from right, are cartridge converter, and the rest are piston-fill.

Piston Fillers and Vacuum Fillers Are More Fun

Even though I’m not a true filling-system snob, and frankly the majority of the pens I use on a daily basis are still cartridge-converter, I get the most enjoyment out of my piston and vacuum fillers. For those who may be new to fountain pens and unfamiliar with the terminology, a piston filler uses, well, a piston mechanism to draw ink into the pen when you dip the nib into an ink bottle and rotate the piston knob. A vacuum filler, such as the Pilot Custom 823 or TWSBI Vac 700R, takes in ink when you submerge the nib-end of the pen in an ink bottle and depress a plunger to create negative pressure. Both types of pens hold more ink than your typical cartridge/converter pen because the entire pen body becomes an ink reservoir, as opposed to a smaller plastic tube (i.e., a cartridge or converter) inside the barrel. In my opinion, this increased ink capacity is the primary benefit.

But piston fillers don’t need to be expensive. TWSBI makes a wide range of piston filling fountain pens for as little as $32.

But piston fillers don’t need to be expensive. TWSBI makes a wide range of piston filling fountain pens for as little as $32.

That said, another huge part of why I love writing with a fountain pen is a sense of not just nostalgia but continuity - there’s something inspiring and even motivating about filling a pen and writing the same way that people did nearly a hundred years ago. For this reason, after cartridge/converter, piston fillers are probably the second most-represented category of fountain pens in my own collection, and what I recommend to most people as a first “upgrade,” followed by the vacuum filler.

Pros:

  • Huge Ink Capacity. Piston fillers and vacuum filler fountain pens can easily hold up to 2ml of ink per fill, and sometimes more. For me, that means I’m good to go for at least two full days of writing. Vacuum filler pens can hold a bit more ink, but as I discuss below, sometimes these are a bit more difficult to fill to capacity.

  • Sustainability/Less Waste. Using a fountain pen that exclusively fills from an ink bottle creates less plastic waste than using a cartridge/converter system. Even if you use the converter, those don’t last forever, as I note above, requiring replacement. If you’re focused on using fountain pens because you like the idea of not contributing to the endless morass of disposable ballpoints, rollerballs, and gel pens clogging landfills, then you may want to take things a step further and forego cartridges and converters.

  • Typically Higher Quality. Because piston and vacuum filling systems take more work to build, as a general matter these filling systems are found in higher-quality pens that may or may not be a pen company’s “flagship” pen. A piston or vacuum filling system is typically built to withstand the test of time, whereas I’ve had converters wear out or break in less than a year. Again, this is a generalization - there are very high quality cartridge-converter pens out there, and some very badly made complex filling systems, but overall I find this accurate.

Cons:

  • Generally More Expensive. With greater complexity and quality often comes greater expense. TWSBI and PenBBS are the two main exceptions to this rule, with TWSBI making both high-quality piston and vacuum fillers for well under $100. While PenBBS makes an exceptional vacuum-filling fountain pen (the No. 456), their pistons leave something to be desired.

  • Only Uses Bottled Ink. If you want to be able to refill one of these pens while you’re traveling, you’ll either have to bring a bottle of ink or a traveling inkwell. That can be an inconvenience for some, myself included, and I often opt for cartridges when I travel, or I make sure to fill one of my larger vacuum filler pens to capacity before I leave.

  • Messier to Fill and More Difficult to Clean. Cartridge/converter pens are easier to clean because you can simply unscrew the nib section and flush water directly through the feed. In a piston or vacuum filler, you basically have to work the piston or plunger mechanism multiple times until the water runs clear, which can take a while. This can be a real pain, especially if you’re changing colors. Moreover, any time you fill the pen from an ink bottle, you have the risk of a spill, which doesn’t exist with a cartridge.

The Pilot Custom 823 is probably my favorite vacuum-filler.

You can see the plunger rod through the transparent barrel. For a demonstration of how to fill a vacuum-filler pen, Matt’s video over at The Pen Habit has a useful demonstration.

Yes, I Know There Are Other Options Out There

Including eyedroppers, pump/vacumatic fillers, aerometric, bulk/syringe fillers, magnet fillers, etc. But other than maybe the Opus 88 Japanese-style eyedropper system (which I very much like), the three filling systems I’ve discussed here are the ones most pen users are likely to encounter on a regular basis, especially those new to the hobby. I may even publish a follow-up post on some of the less common variants, and video demonstrations of how exactly to fill and clean each type of pen.

What are your favorite filling systems, and why? Does anyone stick to just one? I want to hear from you!

This post does not contain affiliate links. The Gentleman Stationer is supported exclusively by subscribers to the T.G.S. Patreon and via purchases from the T.G.S. Curated Shop.

In Editorial Tags Filling Systems, Editorial, Guide, Fountain Pens
11 Comments
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