I had a teacher at school who would refuse to mark anything not written in blue ink. Fountain pen, mind: never ballpoint. Biros were banished – I can still remember trying to get to grips with changing the cartridge in my first fountain pen during my first week there. I was six years old, and it did not end well.
Likewise, at university we had a lecturer who was philosophically opposed to black ink; it reminded him, he said, of a “geriatric spider, crawling to its death”. He may or may not have been the lecturer who took charge of the “Gothic literature” part of the course. I couldn’t possibly comment.
Green ink, of course, is famously connected with MI6, and particularly “C”, and is also regarded as the favourite of nutty-letter writers the world over.
There’s Dragon’s Blood ink, Stark’s ink (no, not that one) and soy ink, but the one I’ve most recently discovered (and of which I’m almost certain my various teachers and lecturers would have approved) is pact ink.
Because, after all, if you’re going to make a deal with the Devil, you might as well do it right. And make sure you use a fountain pen, while you’re at it….