My Nemonsine Singularity demonstrator arrived today. Enclosed with it was a little packet of six cartridges. They are of the standard short international size, but, as I have not used cartridges for years, I was struck by how dinky they looked. But I then reflected that their capacity is no smaller than that of the convertors that I use in all my pens. The convertor itself is bigger, of course, but only because half its length is taken up by the piston mechanism: what I was seeing before me was just a reminder of how meager the capacity of a convertor is. That gave me the idea of looking into my store of cartridges---I have some that I bought many years ago and others that have come with pens---to see if a longer and more capacious one would fit into the pen. Sure enough, it turned out that a Waterman cartridge is of almost identical dimensions to those of the convertor and seemed to fit into the barrel with the top at just the right point. When I inserted the cartridge into the nib section, I found that it could be inserted into---and also removed from---the barrel without difficulty.
Here is the pen, with its convertor and a couple of old cartridges (depleted by evaporation, apparently) alongside it:
I have never made a pen into an eyedropper-filler, and I hesitate to do so, for fear of doing something wrong and making an inky mess. But, since I already have one of those syringes for fountain pen ink, which hitherto I have used only for refilling convertors, I am thinking that, after I have exhausted this cartridge, I might see if I can rinse it out and refill it with bottled ink (which is apparently the main purpose for which those syringes are sold anyway!).
Oh, by the way, I love the smoothness of the nib. Unfortunately, I am never entirely comfortable with a lightweight pen, but this one has such a good nib, and so far seems to be a facile starter, that I expect to make frequent use of it for shorter writing tasks. Also, I discovered that Waterman Blue is a rather nice-looking ink.
Edited by Miles R., 30 June 2012 - 03:05.