With careful transport in cases, hardly any problems are to be expected; in the grooves, however, through reaction with skin sweat an oxide layer can form that is mostly easy to remove. Problems with the rubber surface are known but not universal. A repair, e.g. with a defective cap thread, is only worthwhile if one wishes to continue to use the writing instrument; after the exchange, warranty on the replaced parts again exists. As an alternative, Pelikan was discussed; the ductus does not appeal to everyone; personally the StarWalker was preferred.