I've been experimenting with permanent marker on some plain china plates I've had forever. Fired the plate at 180 degrees C for half an hour in my domestic oven. After it had cooled, I washed the plate with Pril and was happy to see it didn't come off. Hopefully, it'll stay through multiple washes.
I'm now enthused enough to doodle on every bit of plain unadorned china I can find. Already started on my next plate.