I've recently tried Midori/Md b6 slim and really love the size - seems to be just perfect for me: compact enough for edc (the regular TN/a5 slim size was slightly too big)
What is so special about the Stalogy B6 notebook? - NishuraEast - Japanese Design & Culture Online Blog
Notebook in Charcoal Grey - B6 | Appointed Notebooks | Papersmiths
Hightide Penco Soft PP Notebook - Blue - Squared - B6 — Libraries and Archives Paper Company