According to Montblanc service, flushing with clear cold or lukewarm water suffices; after flushing, the pen should lie open so the water residues can evaporate. A piston converter is not strictly necessary. With heavily dried ink or crusts, e.g. after leaked cartridges, soaking, an ultrasonic bath with distilled water or, if needed, sending in for inspection helps. An inspection at Montblanc costs between 39 and 49 euros, without nib exchange. Certain inks, especially iron-gall-containing black-blue cartridges, attack material and gold plating; iron-gall-free alternatives like Pelikan cartridges are recommended. Cleaning the Bohème with retractable nib requires, due to the delicate mechanism, other precautions.
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