@paradoxmo OOOH. Considering that one reason I considered the Tabasco bottle was to solve precisely this problem (using a syringe to transfer those last CCs out of the original bottle into the tiny bottle), that may indeed be the implement I'm looking for! Thank you!

(Looking closer at the product, it may or may not work with my converters. At that price point, though, the experiment might well be worth it.)

@paradoxmo I honestly don't know. They were just called "universal" when I bought them at my local stationers, but when I tried buying them again later, the ones *then* called "universal" didn't fit my pens like the other ones did. So I suspect what I have isn't nearly as standard as I'd hoped it was.

In any case, what I've got fits my old Sheaffer "scholars" (both the one with red barrel and the one with the clear barrel). That might give some indication of tip size.

@NicoleJLeBoeuf I think Sheaffer School pen uses Sheaffer carts, so what you may have gotten are Sheaffer converters. They might have been labeled “universal” because they fit all Sheaffer pens.

The one usually called “standard international” (not a real standard) is Pelikan. But because it’s not a real standard, not all converters that claim to be “international” work in every pen. It’s honestly a bit of a mess and the best policy is to just buy whatever the pen maker recommends for your pen.

@paradoxmo If Sheaffer makes a converter that would fit its school pens, my searches haven't turned any up. Their pens that do take converters seem to have different feed diameters (cf. the Agio).

This conversation intrigued me enough to look more closely (with a magnifying glass) for a brand name. Turns out, this "universal" converter's a Waterman.

But so, it turns out, is the "universal" I bought later that DOESN'T fit. THANKS, WATERMAN.

@paradoxmo On the subject of not-universals: I have another, unmarked, converter, that has the right size mouth but that's too wide around the metal "waist". But that metal part can be taken off, very carefully, and the plunger screwed back in, after filling the converter, and THEN it will fit in the barrel of my favorite pen. (cf. https://stutler.cc/pens/converters/index.html, "Sailor converter for slim pens using a standard piston converter.")

The things we do for our favorite writing implements!