Collectors describe the Montblanc service as varied; many reported defects do not originate from factory production but only arise during sale or trial writing in the shop, since the factory's quality control is regarded as very strict. Workmanship faults on clip hemispheres (sharp-edged adhesive surfaces) as well as scratches and wave effects on the ink window are sometimes not faulted by the service but accepted as within tolerance, which leads to frustration. Ink leakage at the grip section of a heavily used 146P can be a consequence of a feed clogged with dust and ink residues and is remedied by replacing the affected component. When sending in repairs experienced collectors recommend documenting the matters precisely in writing and, in case of doubt, communicating directly with Hamburg instead of relying on the dealer alone.