What is testliner paper?
Testliner is a containerboard grade made from recycled fiber, primarily old corrugated containers (OCC). It functions as the inner or outer ply of a corrugated board sandwich, the same structural role that kraftliner plays. The fiber stream is shorter and weaker than virgin kraft pulp, which shows up in lower burst and ring crush numbers. Testliner compensates with lower cost, better availability near urban recovery streams, and an easier sustainability story.
The name distinguishes it from kraftliner. Testliner grades are classified by recycled content and strength: Testliner 1, 2, and 3 in European convention. Testliner 2 is the most common traded grade. European containerboard mills produce roughly 27 million tonnes of recycled liner and fluting annually per CEPI.
How is testliner made?
The mill receives baled OCC and breaks the bales in a pulper. Contaminants are screened out: wires, plastics, staples, hot-melt glues. The pulp is cleaned, sometimes deinked, and sent to a multi-ply former. Testliner is almost always produced as a two-ply sheet. The top ply is the better, cleaner fiber (for appearance and print). The back ply uses the residual and cheaper stock.
Pressing, drying, and calendering follow the same mechanical sequence as kraftliner production, but the energy draw is lower because recycled fiber needs less chemical cooking. A typical testliner machine runs at 1000 to 1400 m/min.
What grammages does testliner come in?
Testliner is produced from roughly 100 g/m² to 200 g/m². The heavy traded grammages are 115, 125, 140, 150, and 180 g/m². Some mills offer 90 g/m² lightweight testliner aimed at e-commerce applications where box weight is a cost lever. Most purchasing specs default to 140 g/m² as the general-purpose grade.
Testliner vs kraftliner: when do you choose which?
Testliner wins on price and carbon footprint per tonne. Kraftliner wins on strength and moisture resistance. Box designers default to kraftliner on outer plies for exports, humid storage, and stackable pallets. They default to testliner on inner plies and on boxes with short lifespans. Many boxes use both, kraftliner outer and testliner inner, to balance performance and cost.
WPI's kraftliner vs testliner comparison runs through the spec-by-spec differences.
Who are the main testliner producers?
Europe leads by volume. Smurfit Kappa, Mondi, DS Smith, Stora Enso, and Hamburger Containerboard operate the largest testliner machines in Germany, Italy, Spain, Poland, and Austria. Recycled furnish density drives this: dense urban populations produce more OCC, which feeds local mills. The United States has a large but fragmented recycled containerboard industry, with Pratt Industries, WestRock, and International Paper the largest operators.
Asian testliner capacity expanded sharply after 2018 when China's National Sword policy reshaped global OCC flows. Nine Dragons Paper (Hong Kong and Vietnam) now runs some of the largest recycled containerboard machines in the world.
What certifications apply to testliner?
FSC Recycled and PEFC Recycled are the relevant chain-of-custody labels. EU Ecolabel and Blue Angel apply to some testliner grades that meet the stricter recycled content thresholds. Food-contact testliner requires specific barrier treatments because recycled fiber can carry mineral oils and printing ink residues that migrate under heat.
Frequently asked questions
What is testliner used for?
Testliner is the outer or inner liner in corrugated boxes, particularly for domestic distribution and short-lifecycle packaging. It is the dominant liner grade in European corrugated board by volume.
How is testliner graded?
Testliner 1, 2, and 3 in European convention, sorted by strength and recycled content. Testliner 2 is the most widely traded. Testliner 1 is closest to kraftliner in strength. Testliner 3 has the lowest burst and ring crush values.
Is testliner cheaper than kraftliner?
Yes, typically 15 to 25% cheaper per tonne. The gap widens when virgin pulp prices rise and narrows when OCC becomes scarce, as happened briefly during 2021.
Can testliner carry food?
Testliner can hold food only with a barrier layer or a specific food-contact grade. Recycled fiber can contain mineral oil aromatic hydrocarbons (MOAH) and printing ink residues, which is why regulators like BfR in Germany set migration limits.
How much recycled content does testliner have?
Most commercial testliner is 95 to 100% recycled. A small virgin fiber addition (typically softwood kraft) is sometimes blended into the top ply for strength and printability. Full 100% recycled testliner is standard in Germany and Italy.
What is white-top testliner?
White-top testliner has a bleached recycled top ply, providing the print contrast of kraftliner at a lower price. It is the fastest-growing testliner subcategory because e-commerce demands box branding without the premium of kraftliner.