I love this because this is what my journal looks like!!! I can relate...I keep one next to bed and when the world gets too dark for me at times, sketching these zendoodles as I call them, brings back the light. :)
THIS IS SUCH A GREAT SKILL TO LEARN!!! How to bind your own notebooks/sketchbooks. "OP said: I've done it several times using old hardcovers on the outside. This tutorial is my bible for ANY diy book binding."
Nagai Hideyuki uses two sketchbooks to create 3D illusions. I was thinking this may be possible to do on the street/buildings with chalk, but in order to view it correctly everyone would have to be the same height, so that probably wouldn't work.