Choosing the right nib width is one of the most important decisions when buying a fountain pen and depends strongly on handwriting size, paper used and personal taste. The tipping of EF, F and M nibs is rounded at the front, allowing writing from various pen positions; they are particularly suitable for beginners and daily heavy writing. B and BB nibs are ground flat at the front, leaving a horizontal stroke under the tip and producing a wider line. OM, OB and OBB nibs are ground at an angle and require a specific pen position; in skilled hands they enable calligraphic effects, but with the wrong grip they can scratch and are unsuitable for left-handers. At Montblanc the nib can be exchanged free of charge within 14 days of purchase; a later exchange is possible against a repair flat fee, provided the nib is unused and as new.