We have replaced nearly every door in our house (
our interior doors here, our kitchen exterior door here); the only original doors left are our front door (
which we have plans to give a makeover to) and this pocket door, which leads from our master bedroom to our en suite bathroom.
I love it so much.
The door is so old that it already had lost all its sheen, so all I did was wipe it down with some diluted vinegar and got to work rolling on the paint! It turns out, hollow-core, flat panel doors make great surfaces for chalkboards. Just be sure to let the paint completely dry and then condition it by rubbing a piece of chalk all over the surface before writing on it.