How do you get the calligraphy brush in fruit ninja?

To unlock the calligraphy brush in Fruit Ninja, you need to complete certain achievements or milestones within the game. This typically involves slicing a specific number of fruits or achieving a certain score in different game modes. Once you've met the requirements, the calligraphy brush will become available for use in your gameplay. Be sure to check the game’s achievements menu for specific tasks needed to unlock it.