Collectors regard it as unlikely that the clog was caused by the Montblanc ink itself; a pre-existing damage or chemical reaction through mixing different inks on the change is suspected. Before filling with a new ink, the pen should therefore be flushed thoroughly. As a reliable alternative the ink manufactory Jansen (de-atramentis.com) is recommended, which offers document-proof inks in numerous, also discreet colours. Own ink mixtures are regarded as risky without experience values.