Writing data to printed matter with embedded wireless devices

A method of writing digital data to a plurality of printed business cards provided in a printed sheet, each business card comprising a wireless communication chip to which the digital data is written, the method comprising:

• determining relevant pieces of digital data corresponding to the printed sheet;
• writing, using a plurality of wireless communication devices, the relevant digital data to each of the wireless communication chips;
• testing each wireless communication chip to determine if there are any inactive wireless communication chips for which the digital data has not been successfully written to the wireless communication chip;
• and
• enabling positive visual identification of the inactive wireless communication chips by:
• illuminating one or more positions on the printed sheet where an inactive wireless communication chip is located;
• illuminating one or more positions on the printed sheet where an active wireless communication chip is located;
• or
• illuminating all positions on the printed sheet where a wireless communication chip is located, the illumination type differing between positions with and without an inactive wireless communication chip.