Translations:Funzionamento di una penna stilografica/4/en

The basic concept on which a fountain pen is based since then is that of a tank from which the ink can only escape through a very small opening. The opening must be small enough to prevent the ink from escaping spontaneously due to the combination of surface tension and atmospheric pressure. Both forces are necessary, as anyone who has found themselves with the pen dripping in the presence of cracks in the tank or a poor seal of a filling system will have noticed.