Monteverde fountain pens can be refilled with standard international-sized ink cartridges or with an ink converter and any brand of bottled ink.Colorado Pen offers international-sized ink cartridges in 12 different colors. This specially formulated ink helps keep your Monteverde fountain pen writing smoothly.If you need an ink converter, those are offered below. Then choose a bottle or two if ink from our large selection. Colorado Pen ink arrives in a huge 90ml bottle. Pelikan offers standard ink or its premium.