Digital watermarks for packaging
Invisible codes printed across a package tell sorting cameras what the item is made of and whether it held food, so it can be sorted precisely.
The HolyGrail 2.0 industry initiative, run through the European brands association AIM, has tested watermark detection on semi-industrial and industrial sorting lines. Watermarks can separate food-grade from non-food packaging, which is key to closing the loop for food contact plastics.