You can paint on plate or any glazed ceramic using Enamel Paint. However if you need to use it and washed, it would be a good idea to bake it in the normal oven or Microwave (convection) for 30 mins at 150c. It will make the paint more permanent and robust. Especially after you have dried and cured it for a couple of days.; If it is only for decoration you don't need to bake it. Just let it cure by itself for a couple of days (it is air-dry).