Every spiral-bound notebook or sketchbook I've ever seen had the bindings on either the long or short edges. But Japanese stationery brand Inkaren produces these Diagonal Ring Notebooks, which use a lot less material for the binding: The design was "born from breaking free from the unconscious limitations of how the rings should be attached," the company says. "The diagonal rings don't get in the way when writing, and the pages turn smoothly. The cover is made of special paper with a sturdy, leather-like texture, while the pages inside are made of paper chosen for its writing comfort. One edge is held in place with elastic, so it won't easily fall apart in your bag." (If you're wondering why the binding is in the top right corner, rather than the top left as you might expect, in Japan it's common for books to be printed from right to left.) They come with blank, lined or dot-grid pages. They also make a notepad version. While these are affordable in Japan—the 50-page A5 notebook size runs the equivalent of USD $8—imported ones run more than twice that.