When it comes to the Rolex watch collecting world, the fabled 'underline' has been a mystery.
A Submariner or Daytona or Explorer with an underline on its dial is worth easily 1000% more than a non-underline version (that is not an exaggeration either).
There is absolutely no difference between the watches other than the tiny bit of faded paint, but its value is, as mentioned, very different.
Turns out it was all an elaborate April Fools joke by some Rolex collector! - let's call him Bubba to protect his identity.
It was easy for Bubba to make 'underline' Rolex dials since no one expects them to be pristine and they can't be authenticated by Rolex. So a faded underline would do, especially since his canvas was always original authentic Rolex dials and watches.
Of course, Bubba didn't expect collectors to be so stupid and actually fall for his joke, but Bubba forgot one of the oldest marketing tricks in the book: if you want to sell something ugly or in this case, without true substance, you have to attract the dumbest consumers in the world (most rich people). To do this, simply make your item rare and crank up the price and it will sell!
It's gotten to a point, where for example, a regular non-underline Explorer from the 60's is worth around $8000-$10,000, but an 'underline' version will go for close to $100,000!
Bubba is now laughing all the way to the bank, while unsuspecting Rolex collectors brag about their "underline" watches saying "it's all in/about the details".
Incidentally, this has led to a spike in values of other "paint-related innovations", even from other brands. For example, a "Tiffany Dial" Patek where it's dial is stamped (using paint) with the Tiffany Jewelry Company logo is also worth considerably more than a non-stamped version.
Of course, as I mentioned right off the top, this was all one big April Fools' Joke from way back when.
...or is it?
Next thing you know Rolex will start using the word "perpetual" as a synonym for "automatic", knowing full well that in the watch world, "perpetual" has long been reserved to refer to "perpetual calendar" movements. A serious complication that carries serious prestige, and is a complication that Rolex has never made! All in an effort to dupe your average consumer.
But that's just silly... even for April Fools... I mean, who'd be so dumb to fall for that, huh?