Scratch marks above the thread from screwing the cap on and off are a known and mostly normal use phenomenon but do not occur equally strongly on every model and can be material-dependent. Collectors successfully use polishes like 'Wenol' or the motorbike-related 'Unipol' (source e.g. Hein-Gericke) to polish out the scratches. Montblanc itself, however, advises against such agents and officially recommends only clear cold or lukewarm water and a soft cloth, since polishes always remove some material. On valuable or rare pieces the trade-off between visual improvement and long-term material preservation must therefore be weighed.