The nice thing about ring-bound sketchbooks is that they open flat; the bad thing about them is that rings get caught and deformed or even unravelled.
After having to pull my sketchbook from my bag hard (and damaging one ring in the process), I wondered if I could put a spine over the rings to protect them.
So for my first try I used Canson paper. It looks like this might work (we’ll see), but the problem now is that the sketchbook no longer opens flat. Maybe a cloth spine would be better, but I don’t have a second sketchbook to try this out. Maybe I’ll rip the spine out and replace it with a cloth one if it doesn’t work or if it breaks.