The philatelic issue prepared by CTT to celebrate the 2019 Christmas was a world premiere: the guiding star had a LED light, activated when in touch with a smartphone. It was the world's first postal stamp to work like this.

With a complex manufacturing process, and because the LED is inserted in the paper itself, this innovation was the result of a partnership with the startup Mater Dynamics, that developed all technological features.

To make the star shine, you just had to put the stamp next to a smartphone with the protocol “Near Field Communication" (NFC). This function, usually used to send and receive data or make payments, enabled the communication with the LED, automatically activating the intermittent light.