Eyedropper Fountain Pens Opus 88 Franklin-Christoph

To Eyedropper or Not to Eyedropper, That Is the Question

July 3, 2022

As part of this general trend of downsizing everything to a more manageable size, I’ve been trying to write dry all of the various fountain pens that I have inked up, and wow, is that hard to do when so many of them are cartridge-converter pens set up as eyedroppers. I go back and forth on whether, overall, I enjoy eyedroppering. While it’s nice to have the ginormous ink capacity, I’m not sure that convenience outweighs the various downsides given where I live and my current work/life situation.

A Bit of Background

For those new to pens, an “eyedropper” or “eyedroppering” is when you manually fill the barrel of a fountain pen with, well, an eyedropper directly from a bottle of ink. In today’s fountain pen market, there are two types of eyedroppers: Japanese-style eyedropper pens, which comes equipped with a valve system you can use to prevent leaks when you’re not writing, and the “converted” eyedropper, which is essentially a cartridge-converter pen sealed in a manner that allows you to use the full barrel as an ink reservoir. Eyedropper fountain pens can be great for those of us who do a lot of writing, as they can easily hold 3-5ml of ink in the barrel, depending on the size of the pen.

The Schon DSGN Ultem Fountain Pen in Amber (right) is eyedroppered.

To Eyedropper, or Not to Eyedropper

At this point in my fountain pen “career,” I’m not as much of a serial ink changer and mostly enjoy using the same handful of colors, so I can appreciate not having to refill fountain pens very often. That said, the recent hot weather here in balmy Tennessee reminds me of the many downsides to eyedropper fountain pens, namely drastic temperature swings moving outdoors to the car to the office, which causes the pen to burp - no, belch, ink into the cap unless there’s a valve mechanism like that available in the Opus 88 series. For this reason, I’m personally moving away from eyedroppers in favor of other filling options, unless the pen in question has a shut-off valve.

The sections of the Schon DSGN Engineered Plastics Fountain Pens come with o-rings installed. No silicone grease is necessary, though some people choose to use it for double protection against leaks.

For those who live in more moderate climates, or who view maximizing ink capacity and eyedroppering as a challenge they absolutely cannot pass up, there are a few things you can do to ensure that your eyedropper fountain pens behave and don’t cover you in ink.

Add O-Rings or Silicon Grease. If you don’t seal the threads around the section and the screw in nib unit, ink will eventually migrate up the threads and leak. Silicon grease is inexpensive and can be purchased from many pen shops. You only need to use a small amount (just enough to coat and fill the area between the threads), and for the section, a thin rubber o-ring will work as well. (Schon DSGN plastic pens, discussed below, already come equipped with o-rings and “eyedropper ready”.)
Fill ‘er Up! If you’re going to be flying with the pen, or otherwise moving between locations with large temperature or air pressure swings, make sure the pen is full before travel. It’s counterintuitive, but a full pen without any air in the barrel is much less likely to leak. The number one cause of fountain pen “inkcidents” is air expansion due to shifts in temperature and pressure, which causes air in the barrel to expand, pushing ink out the nib. For more on traveling/flying with fountain pens, check out this post here.
Keep the Pens Nibs Up. The main reason I prefer the Opus 88-style eyedropper pens is because you don’t have to worry about this factor. I’m back to commuting 3-4 days a week, so my pens are going with me in the car each day. In addition to the wild temperature swings we’ve been experiencing, I’ve had issues with ink leaking out if my briefcase falls over or my pen case shifts sideways, not to mention if I’m flying and have to slide my carry-on bag under the seat or into the overhead compartment.

Fountain Pens Suitable for Eyedroppering — Franklin-Christoph Model 20 (left) and Model 03 (right, orange pen) generally make good eyedroppers if you remove the converter and apply grease.

What Are the Best Fountain Pens for Eyedroppering?

Generally speaking, any plastic or acrylic pens without holes in the barrel or internal metal parts can be eyedroppered. (Metal doesn’t play well with liquid, though some people have had success with non-reactive titanium. Personally, I don’t tempt fate.) That said, there are a few brands that market their pens as “eyedropper friendly,” with caveats. Note that these will all require some work on your part to convert from cartridge-converter to eyedropper, as I’ve noted above, with the exception of the Opus 88 eyedroppers.

Most Franklin-Christoph Fountain Pens. I’m partial to the Model 20, which has a slip cap and a No. 6 JoWo Nib. Their smaller pens that feature the No. 5 JoWo nib also have better inkflow when eyedroppered, in my opinion. (This is due to the nib and feed, not the pen design.)
Schon DSGN Engineered Plastics Collection. You can read my full write-up here, but as I mentioned above, these pens come equipped with multiple o-rings to make them as eyedropper-friendly as possible.
Most Acrylic or Ebonite Bespoke or Custom Pens. Buy a pen from Shawn Newton or Edison Pens, and you can probably eyedropper it, provided you add silicone grease or an o-ring. If you’re ordering a custom pen specifically to be used as an eyedropper, let them know and they may be able to design the pen to maximize the ink capacity.

I hope you found this post helpful! Going forward, I’d like to write more of this type of “Fountain Pens 101” content. If there are topics that you’d like to hear or learn more about, leave a comment or drop me a line via the “Contact Me!” page. I’d love to hear from you!

NOTE: We are clearing out a lot of our store in anticipation of a site redesign/redirection. Take 10% off all orders using the coupon code SUMMER at checkout, in addition to already low clearance pricing on certain items. Excludes certain brands, including TWSBI and Lochby.

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Pen Review: Opus 88 Omar Demonstrator

October 17, 2020

Those of us with occupations that involve significant amounts of writing are constantly on the lookout for comfortable pens with a reliable nib and a large ink capacity. Time and again, whenever I’m asked for such a recommendation, I keep returning to Taiwanese brand Opus 88. If you aren’t looking for flash or luxury, and you simply want a large, lightweight fountain pen that you’ll have to refill infrequently, the brand should be at the top of your list.

Each Opus 88 Fountain pen comes with a glass eyedropper in the box. Montblanc Hitchcock not included.

While Opus 88 has been at the vanguard of the recent trend towards ever-larger pens, they take a different approach in that their larger writing instruments are actually designed to maximize comfort and ink capacity, not to showcase rare materials or to drive up the price point. The “Omar” fountain pen, the model I’m looking at today, might be one of the largest fountain pens I’ve used recently, but it’s also one of the most comfortable, and it holds roughly 3.5ml of ink!

Ok, but there are tons of humongous acrylic pens on the market these days that you can turn into an eyedropper relatively easily. What makes Opus 88 unique? Opus 88 uses what’s known as a “Japanese Eyedropper” filling system, which incorporates a “piston” that, when closed, activates a system of stoppers and gaskets (o-rings) to minimize the chance of leakage. One drawback to “hacked” eyedropper fountain pens is that they tend to burp ink into the cap when the pen gets jostled in a bag, or when the pen is exposed to fluctuations in temperature and air pressure, such as in the car or on an airplane. Before Opus 88 brought this filling system into the mainstream, Japanese-style eyedroppers were typically found on much more expensive urushi pens from brands such as Danitrio.

If you plan on writing for longer sessions with a Japanese-style eyedropper, open the valve to allow a continuous flow of ink to the nib, similar to how you would write with a Pilot Custom 823 or TWSBI Vac 700.

As I mentioned above, the Opus 88 Omar is large, but also quite comfortable. While you may see stock photographs of this pen posted, it’s way too big for me to use in this manner. Since the Omar will likely serve as a desk pen, as opposed to an “on the go” writing instrument, I’m perfectly happy using this pen unposted. The JoWo No. 6 medium nib writes a predictably smooth line, and the eyedropper filling system ensures a steady flow of ink to the nib. The Omar makes a great workhorse.

The Opus 88 Omar does technically post, but not deeply and the pen is so large that it ends up looking a almost clownish.

Takeaways and Where to Buy

Though I was initially skeptical about the size of the Omar, it turned out to be one of my favorite pens in the Opus 88 lineup. If you’re not a serial ink-changer, and don’t mind the relative complexity of filling a pen using an eyedropper, the Omar might just be the perfect choice for your upcoming NaNoWriMo marathon. You can purchase the Opus 88 Omar in a variety of colors and materials from site sponsor Goldspot. The pen pictured here is the clear demonstrator, currently priced at $123.

Pen Review: Opus 88 Koloro Demonstrators

January 27, 2018

Since entirely new fountain pen brands are few and far between, those that do hit the market tend to immediately catch my attention, especially when the pens being offered are in any way unique. Enter Opus 88.

Opus 88 is a Taiwanese company that, from what I have gleaned on pen forums and other “unofficial” (and unverified) sources of research, previously has manufactured pens on a contract basis for other, better-known pen companies. This past fall, they started selling their own "Opus 88" branded pens in the United States through Pen Chalet. The pens apparently have sold very well so far, with certain colors and nib sizes periodically going out of stock.

Design and Build

Opus 88 currently offers two models: a smaller "Koloro" demonstrator that is available in four colors: blue/tan, blue, yellow/tan, and red, and a larger transparent demonstrator with black trim. The Koloro pens feature a unique combination of ebonite and acrylic. The majority of the barrel is constructed from acrylic, while most of the cap and the blind cap are ebonite. The only trim is a somewhat plain chrome clip.

Both Opus 88 models feature minimal branding, just "Opus 88" on the cap. On the Koloro pens, the branding is engraved. On the larger demonstrator, shown below, it's screen printed, which doesn't look as nice and likely won't be as durable.

The transparent demonstrator (also labeled the “Koloro” on Pen Chalet’s website, but I think that may be a typo) is much larger, made entirely from transparent polished acrylic, and features matte black-plated trim. Both pens are well-made for their price point, with smooth threading on the caps, sections, and blind caps, and no readily apparent tool marks or other manufacturing artifacts. For unique pens hovering around the $100 mark, the Opus 88 pens represent good value.

Filling System

All of the Opus 88 pens released to date are Japanese-style eyedroppers. It’s a pretty basic system: To fill the pen, you unscrew the section and use the included glass eyedropper or a syringe to fill the barrel with ink. I haven’t officially measured the ink capacity, but these pens hold a lot. Pen Chalet states that the smaller pens hold 2ml, but my guess would be that this estimate is on the low end. The larger pen holds nearly 4ml, as I was able to get almost an entire sample vial into the barrel. The section on each pen comes pre-fitted with an o-ring to prevent leakage, and I opted to add a bit of silicon grease to the section threads just to be on the safe side, since I travel so much and an accident could be disastrous.

In order to increase ink flow to the nib, all you need to do is open the valve, which unscrews like a piston knob at the rear of the barrel.

A note on the “Japanese-style” eyedropper system: While the Opus 88 pens are fitted with blind caps that unscrew, this is not a piston-filling or converter pen, and the blind cap does not force ink into or "prime" the feed. Eyedroppers are entirely gravity driven. The purpose of the blind cap is to control a stopper, which seals off ink flow from the barrel to the nib so that ink doesn’t leak out when you’re not writing - a common occurrence in eyedroppers without this shutoff valve mechanism. Without a way to restrict ink flow, shaking, drops, and especially temperature and altitude fluctuations can cause the ink in an eyedropper to expand and “burp” into the cap, into your bag, or even onto the paper when you’re writing. If you plan on using this pen extensively at work or while travelling, as I have, the shutoff valve is a good feature to have, and previously I had only seen it on extremely high-end Japanese Urushi eyedroppers such as those made by Danitrio.

A shot of the Opus 88 Koloro demonstrator with the blind cap unscrewed and the valve opened. When the blind cap is screwed all the way down, the plunger/stopper seals off the nib and feed, keeping the ink in the barrel.

The flip side is that in order to write for extended periods of time, you will need to open the shutoff valve by slightly unscrewing the blind cap to allow a continuous flow of ink to the feed, much as you would need to do with a TWSBI Vac or Pilot Custom 823. This allows ink to flow from the barrel into the section and saturate the feed. You can close the valve at this point, and with finer nibs should have enough ink to write for a page or two. I tend to leave the valve open all day while I’m at work, and close it up when I get ready to go home. The system works incredibly well. With the valve open, I’ve never had these pens dry out, skip, or hard-start.

Writing Experience

Opus 88 uses reliable stainless steel German nibs made by JoWo. The Koloro demonstrators use JoWo No. 5 nibs, while the larger transparent demonstrator uses a No. 6 nib. All three of my pens arrived well-tuned and did not require any nib adjustments. JoWo nibs are among the best stock stainless steel nibs, though I do find that the smaller No. 5 nibs work best in eyedropper or cartridge pens because they tend to write very dry when attached to a converter. I suspect this has something to do with the construction of the feeds in the No. 5 nib units, but I haven’t done enough experimenting to say for sure.

Nib size comparison: JoWo No. 5 (left) vs. No. 6 (right)

Both Opus 88 models are quite light, and therefore very comfortable to write with for long periods of time. The Koloro posts easily, even with the blind cap partially unscrewed, and I tend to use the smaller pen posted. The big transparent eyedropper doesn’t post, so it mainly sits at my desk at home.

Takeaways and Where to Buy

As far as I’m aware, Pen Chalet is the exclusive distributor of Opus 88 fountain pens in the United States, though that may change as these pens attract more attention and become more widely available. Personally, I hope they do, because Opus 88 should have a hit on their hands with eyedropper fans who need a pen that holds a ton of ink and who don’t want to worry about the perils of temperature fluctuation and messy ink burps. Eyedroppers aren’t for everybody, however. They tend to be messier to fill and to clean, and if you like the look of these pens I’d recommend that you start out with one of the smaller, less expensive Koloro demonstrators, which is a much more practical size that will appeal to most people.

The multicolor ebonite and acrylic “Koloro” demonstrators are currently priced at $93 (minus whatever discount code Ron has running at any given time). The transparent demonstrator is available for $120 (minus applicable discounts).

Disclaimer: Pen Chalet is a paid sponsor of this blog. I purchased these pens from Pen Chalet at a discount for purposes of this review. This post contains affiliate links.

A Bit of Background

To Eyedropper, or Not to Eyedropper

What Are the Best Fountain Pens for Eyedroppering?

Takeaways and Where to Buy

Further Reading

Design and Build

Filling System

Writing Experience

Takeaways and Where to Buy

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