https://luxipens.com/fountain-pens-in-movies-and-tv/

Fountain pens can be more than just fine writing instruments; they are emblems of status, education, and wealth. Film and television producers (more specifically their creative staff) put a lot of time, thought, and effort into major decisions like whether or not to outfit a character with a fountain pen. Sometimes even the brand and type of fountain pen can provide important insights into the character.