The economic advantage is that larger sheets can be cut into smaller sheets...letter is half 11x17, 11x17 is half 22x17, and so on. That's exactly the same adv

The economic advantage is that larger sheets can be cut into smaller sheets...letter is half 11x17, 11x17 is half 22x17, and so on. That's exactly the same advantage with the 'A' and 'B' series, etc. A2 is exactly half the size of an A1, A3 is exactly half the size of an A2, A4 is exactly half the size of an A3, A5 is exactly half the size of an A4, ......... This means standard size rolls from paper mills. Once upon a time, that was true. Nowadays, most paper rolls are imported into the US. Most paper rolls produced and used around the world are standardised on metric, not imperial sizes, and as such there are larger economies of scale when using the 'A' series instead.