In case anyone is unaware, A0 is 1m^2 in size, and each adjacent number is half the size (i.e. A1 = 500 000 mm^2, A2 = 250 000 mm^2, A3 = 125 000 mm^2, A4 = 62 500 mm^2).

This has the great advantage of allowing documents to be easily up and down-scaled on a photocopier - i.e. an A3 document can be printed at 50% scale on an A4 sheet.

I wonder if anyone ever tried to do something similar with imperial units (AKA English units to the US Americans) - i.e. create sheets of papers with side-length of sqrt(2) : 1, and the largest being 1 square yard or similar.