The ink performs really well in my Platinum Preppy with an F nib. I can’t say whether the ink is too grey leaning on 80gsm copy paper as copy paper tends to wash out ink colour. On better quality paper the ink is definitely black, even in the F nib. I imagine that most people would buy this cartridge to use with a platinum preppy and in that respect it is very economical. It took me about a month of everyday writing to deplete this cartridge. On a technical note: No feathering; No bleedthrough; Dries fast; Pen has never failed to start writing with this ink; & a solid black colour on good quality paper.
