Material Substitution: Every Substrate Has Trade-Offs
- Aug 9
- 5 min read
Updated: 7 days ago
Consumer preference and regulation are both pulling packaging away from plastic and towards fibre. For most brand owners, the instinct is to substitute one material for another and move on. That instinct is where the cost hides. Every substrate carries trade-offs, and a straight swap shifts the problem rather than solving it. The market data makes that clear.
The pull towards fibre is real, and so is the pressure behind it
The direction of travel is not in doubt. The Bain Paper and Packaging Report 2026 surveyed consumers across ten countries and found that paper and glass rank above plastic in every one of them. Regulators are adding to that pull. Recycled content rules are tightening, and Bain estimates a 30 to 40 percent supply gap for recycled PP and PE by 2030. When recycled plastic is scarce and expensive, the economics push even harder towards other materials.
Unilever shows how this plays out in practice. It moved Carte D’Or ice cream from polypropylene tubs to paper tubs in the UK. One driver was the UK Plastic Packaging Tax: the PP tubs could not meet the 30 percent recycled content threshold, so they attracted the levy, while paper avoided it. The paper tub still contains some plastic for barrier and freshness. The switch reduced the tax exposure. It did not remove plastic from the pack.
What the placed-on-market data actually shows
Stated preference is one thing. What brands actually put on shelves is another. The European Commission's Joint Research Centre modelled consumer packaging placed on the market in 19 EU member states between 2011 and 2025. The analysis covers food and beverages, home care, beauty and personal care, and pet food. Together these categories account for roughly three quarters of the European consumer packaging market.
Two findings complicate the fibre story.
First, plastic packaging grew. Over the study period it increased by approximately 11 percent by weight, from 5.4 million tonnes in 2011 to an estimated 5.9 million tonnes in 2025, and by 9 percent per person, driven mainly by PET. Consumers told Bain they prefer paper and glass, yet the market kept adding plastic. Plastic packaging now averages almost 14 kg per person each year, from 8.0 kg in Sweden to 15.6 kg in Germany.
Second, where materials did switch, the direction was inconsistent. The JRC found only seven clear substitution cases across four drink categories over fifteen years, and they pointed both ways. Bottled water moved from glass to PET in Italy, and from PET to glass in Bulgaria. Swedish juice moved from beverage carton to glass. The authors add a caution worth repeating: several of these shifts reflect a changing product mix, such as a move to premium juices that are traditionally sold in glass, rather than a deliberate sustainability choice.
A third point is easy to miss. In the JRC's 2024 estimate, glass accounted for 32.3 million of the total 42.8 million tonnes of packaging placed on the market, largely because glass is heavy. A move to a heavier substrate can raise the tonnage a brand places on the market even when it feels like the greener option. Weight, recyclability and carbon do not always move in the same direction.
Every material carries trade-offs
The Carte D’Or example illustrates a broader point: switching substrates without understanding the trade-offs can carry real costs:
Recycled content targets for plastic are tightening while supply lags behind.
Paper-based flexible packaging can remain significantly more expensive at commercial scale.
Barrier performance for moisture, oxygen and grease is still a development challenge across newer substrates.
Runnability on existing filling lines is not guaranteed when the material changes.
Referring specifically to paper-based alternatives for flexible plastic packaging, the Ellen MacArthur Foundation noted in March 2026 that such solutions "do not yet exist at the scale, cost or performance needed."
Both things are true at once. Plastic recycling needs investment, and new substrates need development time. Neither is a shortcut around the other.
PPWR sets the target, not the material
This is where many teams misread the regulation. The Packaging and Packaging Waste Regulation does not prescribe which materials to use. It establishes requirements and targets covering areas such as recyclability, recycled content in plastic packaging, packaging minimisation, reuse and waste reduction, and it leaves the route to those targets to the brand owner. The recycled content picture shows why the route matters: as we set out in The rPET Paradox, a legal minimum can become an industry ceiling when supply cannot keep up with demand. Reaching a target on paper and reaching it in a way that holds up commercially are two different achievements.
The practical answer is to act before every detail is settled. As we argued in Preparing for PPWR Without Waiting for Every Detail, the fundamentals are stable enough to plan around today, even with delegated acts still pending. What changes is how confidently you sequence the moves.
Make substitution a portfolio decision
A material decision made SKU by SKU almost always defaults to the path of least resistance. A portfolio view asks a harder and more useful set of questions first. Three are worth answering before any switch:
Where does a viable alternative exist today?
Where does the material science need more development time?
Where does staying on the current substrate make more sense than switching?
The JRC data reinforces why this belongs at portfolio level. It found no reliable link between what consumers spend and the mass of packaging placed on the market. Packaging intensity is driven by format, product mix and material density, which vary category by category. That is an argument for deciding pack by pack within a portfolio view, not for a blanket material swap across the range.
Answer these questions across the portfolio and the roadmap begins to take shape: what to switch now, what to hold, and what needs development before a decision makes sense. Material choices then follow strategy rather than the most immediate regulatory or cost pressure.
Key takeaways
Consumer preference and regulation are pushing packaging towards fibre, and the pull will strengthen as recycled plastic supply tightens.
EU placed-on-market data shows plastic packaging still grew 11 percent from 2011 to 2025, and observed material switches ran in both directions, often driven by product mix rather than strategy.
Every substrate carries trade-offs in cost, barrier performance, line compatibility, recyclability and weight. A straight swap moves the problem.
PPWR sets targets rather than materials, so the route to compliance is a strategic choice.
Deciding SKU by SKU defaults to the easy option. A portfolio view sequences switches, holds and development work deliberately.
Material strategy rewards teams that decide with the whole portfolio in view rather than one pack at a time. The work is to decide which materials to switch, which to keep, and in what order.
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