Crafty Crockery Colouring

Apparently, you can write or doodle on dinnerware with a Sharpie marker and bake it at 350°F (180°C) for 30 minutes and the design will stay permanently.

Use white crockery. Make sure it is clean and absolutely grease-free. Remove any stickers.

Any colour Sharpie will do.

Don't know if the result is food-safe.

May not be permanent on some crockery; do a test first. Hasn't been tested in a dishwasher, but appears to be safely washable by hand.

I found it here, where you can see some examples. Cool idea; I must definitely try it.