Montblanc engraves clips only as a monogram, in other words with initials. Some boutiques with a service centre of their own do the work on the premises, others pass it on to the service department. A full name will barely fit legibly on the narrow clip, and on smaller models such as the 145 it will not fit at all. Longer inscriptions, including those filled with colour, are therefore usually placed on the cap or the barrel.
A full inscription can be cut by any jeweller or engraver with a workshop of their own, and specialist pen shops offer the service for a comparatively modest sum. It is worth bearing in mind, though, that engraving by a third party counts as an alteration to the pen: the part that has been worked on, the clip and its gold plating for instance, is no longer covered by the guarantee, and dealing with the manufacturer over other complaints can become more difficult as well.
From a collector's point of view every engraving is a drawback, and on historic pieces a marked one. For anyone who intends to keep the pen and wants to be able to prove ownership beyond doubt should it go missing, the practical benefit of personalising it outweighs that.