I haven't really seen anyone else talk about this or even bring this up, so I figured I'd start it. I think I have finally found why the Moleskine® notebooks are just so damn appealing. They are beautiful. Literally, mathematically, proportionately, and aesthetically beautiful. I had suspected it once before, but I was not convinced until a member of another group pointed this out:
"The large and small notebooks are golden rectangles (1:1.618) and the large cahiers is a root 2 rectangle (1:1.414). These are the shapes of the masters and thank God we can actually get paper preformatted this way in the United States. If you don't know what I'm talking about, it may seem silly or like splitting hairs; if you do know what I'm talking about, you'll strongly agree with me."
Amazing. I am not the only one to suspect or confirm the Moleskine® and Phi association! I had noticed long ago that the proportions to my pocket Mole were extremely conducive to not only sketches, but the formatting of my writing just takes on a life of it's own. One day, out of sheer curiosity, I did the measurements, and lo and behold, the Moleskine® is almost a perfect Golden Rectangle.
I am a fan of moleskine both large and pocket…but my ideal format is the 4.75″ x 6.5″ (approx) of the Excompta notebooks…that’s my “golden” proportion.
The golden rectangle is my favorite shape, for notebooks and many other things as well, and the 3×5-ish measurements of the pocket Moleskine is my favorite size. See http://www.3x5life.com for documentation of that obsession!
If you are fascinated by 1:1.414 you might be interested in an explanation of the International standard paper sizes here:
http://www.cl.cam.ac.uk/~mgk25/iso-paper.html
It’s a fantastic article describing that “the United States, Canada, and in part Mexico, are today the only industrialized nations in which the ISO standard paper sizes are not yet widely used.”