I've lived in both, and... of all the differences, and problems with various formats and standards and things, this one is so far down the list that I've never even really thought about it.

From the article:

> US Letter: 216 mm x 279 mm

> A4: 210 mm × 297 mm

so it's 18mm longer while being 6mm narrower. At that small a difference, I would assume that a preference of one over the other is similar to that of metric vs. imperial - the one you were raised on just seems right.

Which one did you grow up with?

But it is both 18mm and 6mm narrower, so it goes from 1.414 to 1.29 in terms of ratio.

In other words A4 seems 10% narrower in terms of shape, which isn't insignificant.

Having said that, I'd rather keep A4 given the useful properties described in the article.

I grew up with the A sizes of paper and agree with the parent comment. When I moved to the US I was pleasantly surprised by the size/shape of US Letter sized paper.

That's a 9.5% difference in the aspect ratio. I don't think that's small.

For what it's worth: I am a European, still living in Europe and surrounded by A4 and I envy American's US Letter format.

I almost always have the feeling that A4 is too big.

It's just that you can resize everything while still keeping the same portions with the A* paper while with the US formats you just have to redesign everything.

The aspect ratio of 1:sqrt(2) is absolutely critical to the format. You can't cut a sheet in half and end up with the same aspect ratio without it.

If you really want an aesthetically appealing aspect ratio, wouldn't it be 1:(sqrt(5)+1)/2, which is even longer and narrower?

But then I dig deeper, and find this: http://en.wikipedia.org/wiki/Canons_of_page_construction , which seems to indicate that the ideal book page proportions are 2:3, which is again longer and narrower than 1:sqrt(2).

Personally, I find that US Letter is too wide for comfortable reading without using multiple columns of text, and printed manuals using the format are too floppy to be used without a stiff cover page or a binder. And that's just in print. I can't stand it when someone makes a PDF e-book with US Letter sized pages, because it doesn't fit onto any screen that I have without scaling or scrolling. My e-ink screen is 2:3. Most of my computers are 16:9. None of my 5:4 screens rotate to vertical, and that's as close as I can get to 7:9.

How does US Letter even have any fans at all?

Also, in my opinion, B8 seems ideal for playing cards. It is very close to the ID-1 standard, as well. B7 is the same size as ID-3, used for passports.

I used to publish a magazine (in Japan) that was A4. Because of all the ads were sized to fractions of the page it was a big job to change the page size, so we just left it, for years. When I finally had the chance to make a new magazine I went for letter size -- it's a prettier proportion. As the other posters have said, A4 is too tall.

>As the other posters have said, A4 is too tall.

Is it my imagination or are magazines often taller than A4?