I spent last night binding some small blank books for practice. Keeping the tension even on the stitching is tricky, and I have a tendency to make one end tighter than the other, resulting in a book that sort of wants to fall open at one end.
The four smaller ones are Arches BFK, my absolute favorite paper for bookbinding and printmaking. It’s so soft and strong, and it holds up really well to being stitched. The biggest book is regular copy paper–more of an experiment than anything, I just wanted to see how it would take the stitching. It held up pretty well but I think it would probably tear easily if the book got much wear.