My wife bought a PSI fountain pen kit a couple years ago at a symposium and I finally got around to turning it for her for Xmas. So now she wants to know what type of refill it takes. Of course PSI gives no clue as they want you to buy their cartridge refill. I wonder though, if it is a standard refill for other manufactured fountain pen makes. I would assume so, but can find no information on which one this might be. Anyone have a clue?