One rule of magic says:
A magic user’s choice of writing instrument really doesn’t say much about them. Magic is difficult and fickle work, so anything that puts words on paper will do. There is one exception, however, and the reader is strongly advised to take caution; for should they ever observe someone using a fountain pen to take down notes during any performance of magic, an immediate retreat must be performed, since a hand that inks calmly under a storm of spells is truly to be feared.