Preventing counterfeiting is a major challenge in the security printing industry of banknotes. New technologies are constantly evolving to guarantee security and competitiveness on the market. The latest technologies for multilayer compound substrates and multilayer printing have made it possible to increase security and enable the production of more complex designs and customisable products. Quality criteria for multilayer products have nevertheless become more complex. Taking the example of polymer banknotes, this presentation proposes a quality control strategy for multilayer products to validate the conformity of the banknotes.