A method and system providing an anti-counterfeiting label or mark, using ordinary inkjet printers, take advantage of a phenomenon called a coffee ring pattern, something that inkjet printers. Even the same inkjet printer can output different patterns under different conditions. As a result, the likelihood of reproduction of a particular printer's coffee ring pattern using another printer is so low as to be negligible. It is possible to capture images of the coffee rings using a smartphone camera. The coffee ring approach may be used on any labels or packages on which inkjet printing can be used.