Near-infrared spectroscopy (NIRS) is a fast and easy-to-trace measurement method to determine the materials used in packaging. The near-infrared sensor measures the light reflected by the material, and the returned signal is unique for each plastic. With this approach, the different plastics can be identified. Since only mono-materials can be effectively recylced, more attention should be paid to the subsequent development and selection of materials concerning sortability and this should be included in the decision-making process.