Notebooks - grimoires.
My use of notebooks is strictly esoteric. Everyone knows what a grimoire is. Nowadays, they make special notebooks for grimoires that look like ancient, magical books. This is meant to be impressive, but I don't need that. I want to sit in a café, take out my notebook and pen, and spend a couple of hours without drawing unnecessary attention from those around me. So an ordinary notebook works just fine. I had a simple notebook where I kept my notes and research. When it ran out, I decided to get a new one. I needed a book with blank pages. There wasn't one, but there was a book with black pages. I thought it would be fun, so I bought ballpoint pens with white ink. They are expensive, and for one book I used up ten such pens. The book with black pages attracts too much attention, so I also got another ordinary notebook where I write more text and various working notes. I needed a small notebook as a pocket one. In it, I write down methods and reference information that I use. This includes analytical geomancy, binary hyperstructures and spaces, alchemical metaphors, schemas, and diagrams. I really need these notebooks, and I use them constantly. I use a 'Moonman' fountain pen with black ink. That's enough for me.