Sustainability, Trend

HolyGrail 2.0 Completed - Starting Shot for HolyGrail 2030

06/23/2025 | 4 min read

Anita Gruber

The HolyGrail 2.0 project was successfully completed in March 2025. Its goal was to evaluate the potential of digital watermarks for more precise sorting of packaging. After several successful test phases, one thing is clear: the technology works and could become a key lever in achieving a truly functioning circular economy. Now, with HolyGrail 2030, the next phase begins, focusing on industrial implementation

Digital Watermarks - The Key to Precise Sorting

Digital watermarks are tiny, stamp-sized codes that can be printed directly onto packaging. These codes are invisible to consumers but carry vital information, such as material type, product category, or intended use.

Using high-resolution cameras installed on sorting lines, these codes can be detected, enabling extremely precise sorting that leads to higher recycling rates and better-quality recyclates.

Objective: Testing Real-World Feasibility at Industrial Scale

The central goal of HolyGrail 2.0 was to test the feasibility of digital watermark technology for accurate sorting of packaging waste under industrial conditions. The project specifically aimed to assess how well the technology performs on a large scale in commercial sorting and recycling facilities. Another focus was to evaluate sorting performance across different packaging formats and material types.

It becomes possible to distinguish whether packaging was intended for food or other products, for example. This is an important factor in meeting quality requirements for the resulting recyclate right from the sorting stage. The cleaner the material streams are separated, the higher the quality of the recyclate. And that, in turn, is a crucial factor for the future of plastic recycling: only high-quality recyclates can be reused-especially for sensitive applications such as food packaging.

This also ties in with the upcoming EU Packaging and Packaging Waste Regulation (PPWR), which mandates specific quotas for recycled content in certain types of packaging. Without precise sorting and clean material streams, meeting these quotas is nearly impossible. Digital watermarks could therefore become a key technology for making these requirements a practical reality.

The three Phases of HolyGrail 2.0:

Watermarks Ready for Series Production

The final industrial test series of HolyGrail 2.0’s third phase, conducted between August 19 and December 19, 2024, delivered solid data on the use of digital watermarks under real-world industrial conditions. Various packaging types-made from materials such as PET, HDPE, LDPE, and PP, both rigid and flexible-were successfully coded, collected, sorted, and analyzed.

Key results at a glance:

Detection efficiency: 87.9% to 93.8%
Daily detections: nearly 56,000
Total detections: 5.66 million
Uniquely identified packages: 5,949

The technology demonstrated strong robustness under real-world conditions and showed that precise sorting by material type and application category is feasible-an essential step toward producing high-quality recyclates.

With these results, the technology has reached Technology Readiness Level 9 (TRL 9) and is now market-ready.

Next Step: HolyGrail 2030

With HolyGrail 2030, the project now enters its next phase. The objectives are clearly defined: the proven technology is to be implemented across the industry. Not just in isolated cases, but broadly, from packaging production through retail to waste management.

Key focus areas include:

Technical integration of detection technology into sorting facilities
Development and implementation of standardized coding protocols

Alignment with regulatory frameworks such as the PPWR

Training and engagement of all stakeholders along the value chain

This is not only about technical matters, but also about practical feasibility, cost-benefit analysis, and standardization across national borders.

Greiner Packaging: On Board from the Start

Greiner Packaging has supported the HolyGrail 2.0 initiative from the beginning with innovative packaging solutions, such as directly printed packaging and digitally watermarked K3® cups.

Anita Gruber, Global Senior Expert Circular Economy at Greiner Packaging, emphasizes the versatile benefits of digital watermarks but also points to their selective suitability compared to other technologies:

“From our perspective, digital watermark technology is unbeatable when it comes to embedding packaging information. Whether it’s material data for better sorting, content details, or additional consumer information - the range of applications is broad. However, if the sole purpose is to identify and sort food packaging, we see other technologies, such as AI, as a more cost-effective and less complex alternative.”

Anita Gruber, Global Senior Expert Circular Economy at Greiner Packaging

Greiner Packaging continues to support the follow-up project, HolyGrail 2030, as an Associate Member, with the clear goal of helping our customers implement their packaging solutions in the best possible way. HolyGrail 2.0 has proven the scalability of digital watermarking, and in previous project phases, Greiner Packaging ensured that this technology can be integrated into all types of packaging decoration. In addition, we are actively involved in further projects aimed at improving the sortability of food packaging-for example, through the use of tracers or AI-based sorting solutions.