Montblanc recommends to clean your writing instrument approximately every three months to preserve its pristine condition. Especially, if the ink has dried up due to lack of use, the feeder system is blocked, a different colour of ink is to be used, or the ink flow becomes irregular or stops. For cleaning, use only lukewarm water without any chemical products. It is impossible to prevent condensation after the cleaning process inside the cap. Condensation can dissolve remains of dried ink causing a colour change of the new ink. Therefore, always be careful to clean the nib and cap with a lint-free, damp cloth. To avoid leakage, keep the pen freshly filled with ink and carry the fountain pen with nib pointing upwards. Please also note filling instructions.