Much as I enjoy the articles by Dan Wells, I must disagree with a statement he made in his recent article "The Epson P900".
In his discussion of photo frame and photo paper aspect ratios, Dan stated, "Instead, he (Oskar Barnack) gave it (the 35mm Leica camera) a long, skinny frame that has stayed with us for well over a century, and that paper manufacturers have never noticed despite something like a billion cameras made in the past century that use Barnack’s aspect ratio".
In fact, the paper manufacturers have noticed, to the extent that most inkjet photo paper is manufactured in the A series of sizes. All the paper sizes in the A series have the same aspect ratio of √2:1 or 1.4:1. This aspect ratio is close to the 1.5:1 of 35mm and full frame sensors.
An A0 sheet of paper can be cut into two A1 sheets. An A1 sheet can be cut into two A2 sheets, etc., etc. The most common sizes are A4 which is similar to an 8" x 10" and A3 which is similar to 11" x 14".
The number 1.4 works with the paper sizes just like it does with lens apertures. The successive aperture numbers increase by a factor of 1.4 and the successive aperture areas increase by a factor of 2, just as the paper sizes do.
Kind regards to all.