Montblanc fountain pens are typically available in nib widths EF, F, M, OM, B, OB, BB and OBB. The letter O stands for oblique, i.e. an angled tipping. Before buying, it is advisable to try various widths in a specialist shop, since the choice depends strongly on personal taste; the smaller the handwriting, the finer the nib should be. EF, F, M and OM are particularly suited to everyday use such as notes and letters, while signatures look most striking with B, OB, BB and OBB. After purchase from a specialist dealer there is a 14-day window in which the nib can be exchanged free of charge; later swaps are only possible via Montblanc Customer Service against a repair flat fee. In the Meisterstück range nibs have changed visibly over the decades; older 149 models have a bicolour nib similar to that of the 146, while newer 149s are made of yellow gold inside and out, platinum-plated in the middle.