I'm reading Philip Larkin's letters. Whilst he drafted his poems in 2B Royal Sovereign pencils, he used a Fountain pen to write some of his letters. In his letter dated 17 April 1941 he writes, "The writing of this will be awful because I'm being forced to write on the back of an awful nib." On 16 April he calls it a vile pen (no mention of the brand). Considering, he's just survived another round of bombing (Coventry was very badly hit through-out the blitz) the letter reads as rather matter of fact and has some understatement. That said, Larkin was an entertaining letter writer and it contrasts sharply with how people come to view him through his poetry. yes, the themes are in the letter, but there's also a love of jazz and playing with language.