And Comic Sans for letters sent to friends finishing design school, obviously.

There are all sorts of statistical rules falling out of studies about where the long/short divide is, ambient lighting, blah blah blah - but human vision is even more variable than most biological quantities, so in the end general rules are the best one can really do.

Here of course, it's nothing more than rearranging the deck chairs, while the captain targets the next iceberg "to teach the ice a lesson!"