How do you recognise a copy of a black Montblanc Meisterstück rollerball?

At first glance the original and the copy of a black Meisterstück rollerball look very much alike. Three details separate them reliably.

The cap ring: on the original the black rings are made of precious resin and finish flush with the surface of the cap ring. On the copy they are milled grooves that have been filled with black, so the transition is not flush. The cap ring of the copy also has a different shade of gold.

The shape of the clip: the lower end of the original clip is round. Montblanc's clip shape has remained essentially unchanged since the 1940s. On the copy the end is distinctly more angular.

The way the clip is made: a look from the side shows that the clip of the copy is bent from sheet metal — a feature found on a great many Montblanc fakes. If any one of these features applies to a pen, it is a copy.