Joho the Blog
An Entry from the Archives

It's very close. The golden ratio is: 1.618...

7.5 x 12.5 cm is the same proportions as 3" X 5", which ratio is: 1.666...

I've heard people say that 3x5 cards are golden rectangles.

But the Golden Ratio may not be quite what it's cracked up to be.

Well, I'm not sure that's close enough.

We have 12.5 / 7.5 = 1.666...

and to play the game out, the rectangle left after you remove the 7.5 by 7.5 square should have the same proportions, but that's

7.5 / 5 = 1.555

To get there completely, you want 12.135 by 7.5 (4.85" by 3)

or 12.5 by 7.725 (5" by 3.09") which seems sorta-kinda close.

I just ran across reference to the "Golden Ratio" while hunting down something entirely different.

The Optima font was popular on the Xerox Star and its descendents, and it was a common font for Interpress laser printers. I did not know about its commemorative use until just now: http://typophile.com/wiki/Optima