Back to Overview

HolyGrail 2.0: Revolutionising sorting and recycling with digital watermarks

Correctly identifying and sorting used plastic packaging is one of the biggest obstacles to higher recycling rates, and we plan to solve it.
Written by

Gian De Belder

Technical Director, R&D Packaging Sustainability, P&G

I’m excited to share how we are embarking on the most ambitious post-consumer recycling project in the world today. Together with our value-chain partners, including the leader in the polyolefins industry, Borealis, we are aiming to revolutionise recycling through HolyGrail 2.0. This project will significantly improve plastics sorting, addressing one of Europe’s biggest bottlenecks to a truly circular economy of plastics.

Currently, recycling rates in waste sorting facilities are far from perfect. For example, machines are unable to distinguish food-grade from non-food grade plastics, meaning plastics that could be recycled to manufacture new items often have an unsustainable end of life, discarded in a landfill or incinerated. Even though existing barcodes could carry this information, all barcodes on all packaging would have to be facing the sorting line’s cameras to be read – which is an impossible task. But there is a solution: digital watermarks.

In HolyGrail 2.0, digital watermarks will be integrated directly into a mould, or in the design of printed or in-mould labels.

© P&G

These watermarks, the size of a postage stamp, cover the entire surface of a consumer goods packaging. They are able to communicate a wide range of attributes, including manufacturer, Stock Keeping Unit (SKU), type of plastics used and composition for multilayer objects, and food vs non-food usage. When integrated with packaging, the digital watermarks can be detected and decoded by a standard high-resolution camera on the sorting line, which then – based on the transferred attributes – is able to sort the packaging into corresponding streams. Whatever position the packaging is in, it can be identified correctly. As a result of better, more accurate sorting streams, we can achieve higher quality recyclates that benefit the complete packaging value chain.

The digital watermarks were tested in the first stage of the project, HolyGrail 1.0., which was facilitated by the Ellen MacArthur Foundation with the aim of moving closer to a circular economy. As one of our partners, Borealis provided the test samples (embossed HDPE bottles) that underwent successful testing in the proof-of-concept trials. This groundbreaking progress is an example of their EverMinds™ platform in action, a platform established to highlight and accelerate action in plastics circularity, bringing stakeholders together to collaborate and innovate technologies that transform the industry.

Borealis is now part of the leadership team and will be supplying us with good quality recycled resins, to specification in large quantities, for HolyGrail 2.0 (now with over 80 value-chain partners) – which aims to prove the viability of digital watermarking for accurate sorting at a large scale. They will also be supporting the project by helping with intelligent sorting and consumer engagement. One of the HolyGrail 2.0 work streams will be to improve sorting on different polyolefin types in food vs non-food packaging, led by Borealis; as an expert in virgin packaging materials.

HolyGrail 2.0 aims to prove the viability of digital watermarking for accurate sorting at a large scale.

The HolyGrail project is just one of the ways in which P&G is accelerating the transition towards plastics circularity. We are striving to Design-for-Circularity, aiming for 100% of our packaging to be recyclable or reusable, while also reducing the use of fossil-based plastic by half (~300 kilotons/year) so that we rely more on post-consumer resin (PCR) content for packaging, having already achieved our 2020 goal of doubling PCR use to 52Kt/a. We support The Recycling Partnership and The Alliance to End Plastic Waste in delivering scaled solutions that make recycling accessible for everyone, and are working to increase recycling participation through clear and easy package labelling, and consumer communication. And because the recovery of plastics is crucial, we are championing HolyGrail 2.0 to improve sorting – demonstrating how coding packaging can improve the recovery process.

Correctly identifying and sorting used plastic packaging is one of the biggest obstacles to higher recycling rates, and we plan to solve it. #EverMinds #HolyGrail2

We also realise it’s essential to create an end market for the throughput of recycled plastics – there needs to be an offtake of the recycled material to ensure we close the circle (and create valuable business cases). Multiple efforts are happening globally to increase recycled content at all levels, for example Borealis’ EverMinds platform and EU programmes like Circular Plastic Alliance, which aims to use 10MM tonnes/year recyclates in Europe. In addition, innovations like Purecycle (a polypropylene recycling technology invented by a P&G Scientist) provide quality recycled material to improve offtake and drive demand.


These might be internal goals, but they’re something the entire value-chain can play a part in achieving; a circular economy is only possible if we all take responsibility. P&G, and our partners, need to communicate circularity with our professional networks, like Borealis do through EverMinds, as well as educating consumers on the critical role of plastics in society. We must create a reality where consumers see plastic packaging as a valuable resource – just like paper and glass – which we can achieve through education on what happens with plastics at end of life, and how further use in another life is important. If we all work together, a circular future is within reach.

Have some questions about HolyGrail 2.0? Then please get in touch with either myself, Gian Debelder at P&G or Philip Knapen, Application Marketing Manager at Borealis.

Written by

Gian De Belder

Technical Director, R&D Packaging Sustainability, P&G

Print