I've been using these "Ogami Collection" notebooks apparently made from limestone for a while now: https://origin68.com/collections/notebooks-stationery/product

I've been using these "Ogami Collection" notebooks apparently made from limestone for a while now: https://origin68.com/collections/notebooks-stationery/products/professional-black-notebook?variant=7229226053 https://origin68.com/collections/notebooks-stationery/produc... They're like much more durable Moleskins, in my experience.