Neil Gaiman and Notebooks

From The New Yorker's January 25, 2020 profile of Neil Gaiman: "He wears black: black socks, blackjeans, black T-shirts, black boots, and black jackets whose pockets are loaded with small black notebooks and pots of fountain-pen ink in shades like raven." (Emphasis added)

Small black notebooks--Moleskine? And he carries around fountain pen ink in his pockets! Raven ink sounds interesting.