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 31 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 or smaller 30ml bottle. Private Reserve offers cartridges in a multitude of colors and bottles in different ink types.