You can then add a number up to 2 characters, which will appear inside the balloon (this is not mandatory and can be left blank if preferred). The reverse of the mug can be personalised with a message over 4 lines up to 20 characters per line. All personalisation is case sensitive and will appear as entered. What’s more this fantastic mug is available with next day delivery!Hand washing is recommended. Material is ceramic. Perfect for Birthdays.