The problem with metric paper is that A4 sucks for printing text—it’s too wide for a reasonable line length at 10 or 11pt, whence e.g. the sprawling margins of

The problem with metric paper is that A4 sucks for printing text—it’s too wide for a reasonable line length at 10 or 11pt, whence e.g. the sprawling margins of the standard LaTeX classes with the a4paper option; and A5 is definitely on the small side. (A single wide margin beside a long text column, like in the Berkeley physics course, Spivak’s Calculus, or Tufte’s books, is one possible way of taking advantage of wide paper, but it’s not used that often.) A period-2 infinite sequence with alternating 3:2 and 4:3 sheets, which in one form or another has been used for books since forever, would have been better, but apparently the committee(?) did not like it for some reason.