Thing one: identical PCR percentage can deliver totally different press results
We ran side-by-side trials on two board stocks, both marked 30% PCR. Same printing plates, same ink, identical press settings.
Mill A performed really well. Print quality stayed clean, foil stamping adhered reliably, and die cut tools held their usual service life.
Mill B told a very different story. Surface linting was widespread, visible specks appeared across sheets, foil adhesion failed in spots, and our die blades wore down much faster. The reject rate doubled compared to Mill A.
What caused the gap? It all comes down to de inking and fibre sorting standards. Some paper mills maintain strict process controls; others cut corners. The PCR percentage printed on a spec sheet cannot tell you how well the material will behave on your production line.
Our internal rule now: whenever a customer requests high PCR board, we never finalise recommendations until we run physical samples through our own production equipment. Specification sheets are only a starting point, not a guarantee of performance.
Thing two: high PCR boards suffer more under humid conditions
Recycled fibres grow shorter and more brittle each time they are reprocessed. At the same base grammage, shorter fibres mean lower stiffness and weaker moisture resistance.
We completed 72 hour humidity conditioning tests simulating real life ocean container environments. High PCR boards lost far more stiffness than standard virgin heavy stock, and stack compression performance dropped significantly.
We learned this lesson the hard way. Last year, we handled an export shipment bound for Australia. The customer specified high PCR board and turned down our suggestion to complete humidity testing at the sampling stage. When containers arrived, high humidity in the local warehouse softened and slightly warped the cartons. Their automated filling system kept rejecting boxes, forcing them to repack the whole order manually — slow and expensive.
Our position today: if goods travel by sea, head to tropical or subtropical markets, or feed into automated packing lines, humidity and compression tests are non negotiable. Skipping these checks creates expensive risks. A few days of testing avoids major headaches further down the supply chain.
Thing three: boosting grammage can erase your carbon gains
This is the trade off many brand teams overlook.
High PCR board tends to have lower mechanical strength. The quick fix is to increase grammage for extra stiffness. But heavier stock means more material per carton, higher shipping weight and greater freight emissions.
Some of the CO₂ saved by choosing recycled fibre can get partially, or even completely, cancelled out by extra pulp consumption and logistics.
In one of our real test cases: standard grammage 30% PCR board versus thicker 60% PCR stock. The net carbon difference ended up below 5%. On paper, the higher PCR option looked impressive, yet its actual environmental benefit was minimal.
Our practical advice: do not chase PCR percentages in isolation. Work out your package’s true requirements: stacking load, shipping route, and product weight. Ask your board supplier for two to three material options with different PCR blends and grammages. Choose the option that balances performance, cost and carbon impact. Fixating on a single metric rarely works out well.
How Kinghorn Packaging approaches PCR conversations with customers
When a client mentions PCR requirements, we start with three straightforward questions:
1. What is your shipping route? Sea or air, and final destination?
2. Will packing be manual, or fully automated?
3. What is the product weight and expected stacking height?
Then we offer two or three production grade board alternatives from different mills, keeping box design and print files unchanged. Every candidate goes through our full test workflow: printing, die cutting, folding, gluing, humidity conditioning and stack compression. We share raw test data, not subjective opinions.
Bottom line
Recycled PCR fibre is absolutely a positive direction for packaging. There is no argument on that front.
But high PCR content alone does not equal good performing packaging. What really counts is whether your cartons print cleanly, survive transit, and run without issues on your customer’s filling equipment.
If none of your customers have asked for PCR yet, you are not behind. Most brands are still not mandating it. Still, demand is building. Running preliminary tests now puts you in a strong position when those enquiries arrive.
Unsure which PCR level suits your project? Send over your shipping route and packing line requirements. Kinghorn Packaging can carry out free side by side evaluations with real production grade samples. We complete print tests, folding checks and shipping simulation, then deliver a full factual test report. No marketing fluff, only insights drawn from real world manufacturing.
