One place where the metric/American mixup is a regular pain is paper sizes. American scientific journals are generally published on Letter paper, while all othe

One place where the metric/American mixup is a regular pain is paper sizes. American scientific journals are generally published on Letter paper, while all other scientific journals are generally published on A4 paper. The difference in aspect ratio is just enough to cause the bottoms or sides of pages to be cut off if you don't pay attention. One nice thing about the international paper standard is its subdivision property: if you fold a piece of paper in half (along the correct axis), it retains its aspect ratio. That's pretty useful for printing pages 2-up, and for reducing paper waste. It's a similar argument to the "argument of twelves," but it goes in the opposite direction: the metric standard is favored.