John McEnroe Keeps asking why the white lines skid.
Guess he's never painted anything.
As you add coats of paint to a rough surface it get smoother. White
lines are of course the last added and since white doesn't cover over
dark colors well it is either thicker or applied in coats to make sure
colors below don't bleed thru.
There is probably a way to change this, like adding grit to the white
paint. But why, it's part of the game. Also most likely the grit would
discolor the white after a while as it wore thru.
But that's it John. grab some paint and try it some time.

in johnny mac's defense ... this afternoon during the djokovic match, mac sand, "i can't understand why they can't make the white lines not skid -- bake the color on, make them the same texture as the court, get some way of coloring the lines so they are not slick." i don't think he was saying, "i can't understand why the ball skids when it hits the line" as much as, "i don't understand why they can't make the lines white without making them slippery."