A mere enquiry of the serial number to the manufacturer does not deliver certainty, since even counterfeits can be provided with fictitious serial numbers and Montblanc, without inspection, gives no authenticity statement. Certainty is given only by sending the writing instrument to Montblanc; genuine pieces are returned, counterfeits disposed of. By now also very well-made counterfeits exist that are not distinguishable from originals at first and second glance but hardly turn up in reputable shops. An experienced specialist, however, reliably recognises these counterfeits.