Chalkboards are all the rage, either pretend ones, just an image and
some kind of font to make a digital picture, or a real one, painted with
actual chalkboard paint.
The special kind of paint developed for chalkboards comes in several
colors; black (of course) and sometimes a dark shade of green.
There are a few different brands. I've used several, but the biggest
mistake I ever made was to buy an oil based one. Don't do this! It's
almost impossible to get it off your hands, and the smell of the off
gassing is unbearable, especially indoors. Get a water based type only.
The water based chalk paint has a texture that is creamy and goes on easily - but in most cases, unless you have a sprayer, it doesn't go on evenly.
So, celebrate that and make it an attribute! I use a crosshatching pattern to cover the surface of the board, which gives it a bit of texture and looks a lot more rustic - which is all the better, as far as I'm concerned.
The instructions on some types of chalk paint advise you to prepare the finished surface by rubbing chalk all over it, to prevent the lettering from marking it.
Wipe the chalk on, then rub it off with a dry cloth, finishing with a damp cloth to remove it completely. I guess this fills up all the pores of the paint.