Ink Cartridge Stoppers

[Jerry LeMur]

Are you tired of dealing with the hassle of ink cartridges in your fountain pens? Whether you're constantly swapping cartridges for your desired ink color or packing cartridges for your pens while on the go, the fear of ink leakage is a common concern. The traditional solution, using a glue gun, can be a bit finicky. You have to get the temperature just right, avoid melting the cartridge, and hope that your makeshift seal holds up. Not to mention the annoying glue string mess it can leave behind.

Wouldn't it be great if there were a simple and effective alternative to this problem? Well, outside of Gabriel Falcinelli's brass stopper for International Cartridges, it seems like there hasn't been much interest or investment in this area. So, I've been searching for a cost-effective solution, particularly for short international cartridges, as well as Sailor and Pilot cartridges. This scruffy note distills my solutions for these cartridges.

International Cartridges:

One issue with international cartridges is the inconsistent tolerances when it comes to the diameter of the opening. M. Falcinelli's solution works, but it can be a bit costly at around $4 per stopper, not to mention postage charges. His approach involves a metal rod that can be forced into slightly undersized openings but fits well in on-spec cartridges. I've had some success finding alternative stoppers on AliExpress. They might not fit well in cartridges with tolerances below spec, but they work perfectly in on-spec cartridges, like Pelikan's. Plus, they come at a fraction of the cost, often less than a dollar for a pack of 10 with free shipping. Various vendors on AliExpress, search for 2.7mm (TS-2.7) and I got mine here.

Sailor Cartridges:

Slam dunk: this stopper Ali Express. Similar cost as previous, and these work really well, with the Sailor Cartridge's larger diameter. Similar to International Cartridges, search on AliExpress for size 4.5mm

Pilot Cartridges:

I'll admit, I went through some trial and error to find suitable sizes for the previous two options. But when it came to Pilot cartridges, I took the easy route and purchased a box of Majohn A1/A2 empty cartridges that come with their own stoppers.

Platinum Cartridges:

As for Platinum cartridges, I haven't explored this area much, mainly because I don't often use Platinum pens. Sorry about that!

If this simple post encourages someone to take up the baton, or you already have a solution (or improvements on those listed here), please share 😊

[BrassRatt]

Thank you for this exploration!  

 

I'm looking for "standard international short" cartridge stoppers with an additional constraint:  they must be very short outside the cartridge.  My application is in a pen (Edison Collier) that stores a second cart behind the one in use, so that they can be swapped when the one runs out.  This means that a stopper cannot add significant length to the stopped cart. 

 

Nothing I've seen fits this need; the plugs I got from AliExpress are too long already. 

 

Looks like I may have to do some lathe work and make stoppers with thin, wide heads. 

 

Or is there something out there? 

 

[Dillo]

What I do instead of using stoppers is cut off a small section of latex ink sac, and stretch it over the top of the cartridge. The reason why is because anything you stick into the mouth of the cartridge can stretch out the mouth of the cartridge. There is a fair variance in the connectors in pens, so some cartridges that have been already used in one pen may fall off the connector of another pen. Pelikan cartridge filling pens for example are notorious for having small diameter and short connectors. Brass corrodes with ink exposure, so I do not recommend the brass stoppers. Been there done that

[Merrick]

The Majohn Pilot clone carts with stoppers are so good, I’ve got tons of them. I wish they’d do the same for Sailor and Platinum!

[The_Beginner]

mmmm, Do you think a 3d print could be made then the source file shared. hmmmm i feel a new project brewing in my head

[Chris1]

Not tried this as I don't like cartridges but I do have a sheet of neoprene rubber about 4mm thick and a hole punch for leather. Could the two be used to create a little rubber bung of the right size? 

 

Maybe I go into business 😄

[inkstainedruth]

Not sure how I missed this thread before now.

Back when I still used (and refilled) cartridges, I would put a dab of stuff over the end that is the stuff used for making piston heads in converters slide more easily; but it's been so long that I don't remember now what the stuff is called  (it's basically a clear gel that is safe for pen threads and piston heads and the like).  

Ruth Morrisson aka inkstainedruth

[Sporadic Traveler]

On 3/21/2026 at 6:03 PM, inkstainedruth said:

Not sure how I missed this thread before now.

Back when I still used (and refilled) cartridges, I would put a dab of stuff over the end that is the stuff used for making piston heads in converters slide more easily; but it's been so long that I don't remember now what the stuff is called  (it's basically a clear gel that is safe for pen threads and piston heads and the like).  

Ruth Morrisson aka inkstainedruth

 

Are you talking about silicone grease? That would work; did you ever have some of that grease make its way into the feed and cause blockages later?

[inkstainedruth]

Yeah, I think that's what I used.  Don't recall the silicone grease making it into the feed, because I tended to scrape it off before installing cartridges.  But I just found that refilling cartridges was just too much of a PITA, and have pretty much switched over to converters for my C/C pens.

Ruth Morrisson aka inkstainedruth

[Cjtamu]

Unlike the OP I’ve had no issues with a hot glue gun. Dual temp gun on low. @inkstainedruth there are pens like the MB 147 that won’t take a converter so if you want an ink that doesn’t come in a cartridge refilling is your only option. Share your opinion on it being a PITA and have pretty much quit doing it.