It seems like the only company I can reliably find lined paper from is Rhodia. That said their paper is very good, and though it comes in tablets, the pages tear out easily and cleanly so you can pull them out and use them as loose leaf. I’m really surprised how difficult it is to find lined paper from companies like Tomoe River, Clair Fontaine, etc over here where I am. (SE US.) I have to basically import everything, so I’m at the whims of what I can get from places like Goulet, Jet Pens, and Amazon.