Who's coffee is this / coffee cup

The cup design concept can be clearly identify the individual mark for easy identification of each of the coffee cup; the design concept is using the function of the pen and paper into the cup and stirring rod, using stir bar and coffee, you can have the drawing board in the lid easily write a personal mark with the message, no additional tools.
(1)To stir bar (drink stirrer) dipped in coffee, stirring rod tip will retain the right groove coffee ink.
(2) To use of stir bar or mark the message written on the drawing board. Then, the messages are displayed on the drawing board.
(3) We can easy identity each of the coffee cup.