Majohn C4 Fountain Pen Review: An Eyedropper with a Shut-Off Valve

Introduction

If you have a soft spot for clear demonstration pens, the Majohn C4 is hard to ignore. It is an eyedropper-filled fountain pen with a one-way shut-off valve, the same basic idea you will find on some very high-end Japanese pens, and it sells at a fraction of that price. It also has one significant flaw that you should know about before buying. Here is the full picture.

What Is the Majohn C4?

The Majohn C4 is a large acrylic eyedropper pen with gold trim and a Japanese-style one-way shut-off valve, a system found on high-end Japanese pens including some far more expensive models. It is made of acrylic polished to an impressive level: crystal clear, essentially no micro scratches, and every edge you expect to be rounded off is nicely finished. The clear cap and end cap are so clear they actually function as a magnifying glass.

Despite what some online commentary suggested, it is not an enormous pen. It is comfortably larger than a Pilot Metropolitan, but not huge. It is comfortable to use unposted, and it does post, although not very securely, so posting is not really worth the effort.

Out of the box it arrived wrapped in bubble wrap with a protective sleeve rather than a fancy box, which most buyers will not mind. An eyedropper is included, which you genuinely need for the filling system. The pen uses a #6 steel nib available in three widths: extra fine (0.38 mm), fine (0.5 mm), and medium (0.7 mm). The nib is stamped Moonman, while the center band says Majohn; they appear to be the same company using different names.

The Filling System

This is the main reason to look at this pen. It is an eyedropper filler with a one-way shut-off valve. Inside the barrel sits a metal rod with a seal at its end that closes off an upper ink chamber. To fill it, you unscrew the end cap to pull the rod back and open the chamber, unscrew the section entirely, and use the included eyedropper to fill the barrel with ink until it is fairly full.

A useful trick: screw the section back on about two-thirds, hold the pen upside down over the ink bottle, then screw it fully in with the valve open. This pushes a little ink out and primes the feed, so you can write immediately. From there, you can either leave the valve open while you write or close it and open it again when the upper reservoir empties. Opening or closing the valve makes only a modest difference in wetness in practice, not a night-and-day change.

The shut-off valve also adds a layer of security. A classic eyedropper pen can leak badly if the section unscrews accidentally; the extra seal here reduces that risk, even if only psychologically. Cleaning is easier than with a cartridge-converter pen too: unscrew the section, flush out the barrel, flush the section with a syringe, or simply leave it in water overnight. The ink capacity is large. Based on roughly three full eyedropper fills, it is around three to three and a half milliliters, clearly more than any cartridge converter.

Writing Performance

This is where the C4 stumbles, and it is worth taking seriously. The medium nib tested was extremely dry out of the box. Writing with no pressure produced constant skips, because the tine slit is too tight. Strictly speaking, a fountain pen should write under its own weight, and this one does not.

With a bit more pressure than a fountain pen should need, it becomes a genuinely nice writer: broader, wetter, smoother. That confirms the problem is the tight slit, not the feed or the valve. To rule out the obvious objection, the pen was tested with the valve fully open, and the dryness was exactly the same. The valve is not the cause.

Other notes on the nib: it seems to be a nice round nib rather than stub-like. With deliberate pressure there is some line variation, though this is not a flex nib and should not be treated as one. Reverse writing is possible with a bit of pressure and turns the medium into something close to an extra fine. A tight slit is a fixable issue with basic nib adjustment, but if you do not like fiddling with nibs, this could be a real dealbreaker, especially as a first fountain pen.

Things to Consider Before Buying

There are two main drawbacks. The first is the tiny clip, which is genuinely too small to work as a clip. It is unlikely to reach far enough to get any purchase on a shirt pocket. The pen is round with no facets, and the clip works reasonably well as a roll stopper, so it is best to treat it that way. If you carry your pens in a case, this will not bother you; if you rely on a clip, it will.

The second is the dry nib discussed above. That said, the value proposition is strong. The pen cost about $33.87 CAD with free shipping, and AliExpress prices fluctuate, with listings seen around $40 CAD and up. Compared with other shut-off valve eyedropper pens such as those from Opus 88, where the price jumps considerably, the C4 is one of the most affordable ways to try this filling system.

Buying Advice

Buy the Majohn C4 if you want a large-capacity, well-made clear demonstrator with a shut-off valve, and you are comfortable doing a small nib adjustment or asking someone who is. Skip it if you want a pen that writes perfectly out of the box or if you need a functional pocket clip.

Conclusion

The Majohn C4 gets a lot right: excellent acrylic polishing, a comfortable size, big ink capacity, easy cleaning, and a filling system usually reserved for far more expensive pens. The dry nib and the almost decorative clip hold it back, but with a little tuning, it has real potential.