Most pens either ship with or will work with a piston converter. You don't need to mod a pen just to use inks other than those available in compatible cartridge

Most pens either ship with or will work with a piston converter. You don't need to mod a pen just to use inks other than those available in compatible cartridges. E.g., https://duckduckgo.com/?t=ffab&q=fountain+pen+piston+converter&iax=images&ia=images https://duckduckgo.com/?t=ffab&q=fountain+pen+piston+convert...