ARTICLE VENDING MACHINE AND METHOD FOR AUTHENTICATING RECEIVED ARTICLES

An article dispensing machine, system and method for authenticating an article returned to the article dispensing machine and an article for use in such a machine and system. The article dispensing machine comprises an infrared light for illuminating the surface of the returned article, an image capture device for capturing the image of an authentication code on the returned article, and a processor for comparing the captured image to a master authentication code. The returned article comprises the authentication code printed in a carbon-containing ink and a substantially carbon free ink portion printed overtop of and at least partially concealing the authentication code, such that the authentication code is not visible in white light, but becomes visible when exposed to infrared light.