# Kraftliner vs Testliner: Reading the Grades Instead of the Fibre _Both names are entries in a published grade list, their property floors overlap where nobody expects, and a grade reports a minimum rather than a measurement._ **The short answer** **Kraftliner and testliner are grade names in a published list, not two materials.** Each grade sets minimum measured properties, and a code identifies it. **The categories overlap.** One recycled grade carries a compressive floor above kraftliner's, so recycled does not mean weaker once you read by grade. The choice arrives sounding settled. Virgin kraft is the strong one, recycled testliner is the cheap one, and the only question left is what the budget allows. Read the grade list and that account comes apart. Both names sit in the same published document, each defined by minimum properties rather than by what went into the vat. The floors those grades set also cross over, because a recycled grade in that list clears a higher compressive bar than kraftliner does. This reference covers what the grade names mean and the floors each has to clear. It then covers where the categories overlap, why a grade is a minimum, and what to specify instead. - **Grades, not types** - Each with a code - **18.0 vs 19.0** - SCT-CD floor, kraft vs recycled - **3.5 to 1.3** - Burst index floor, top to bottom - **Auto-promote** - Beat a limit, change grade ## The Names Are Grades, Not Materials Both words come from a [published grade list](https://cepi-containerboard.org/display_doc.php?id=2497), now in its sixth edition. The list assigns every grade a numeric code and a set of minimum properties. Kraftliner is the primary-fibre family, predominantly made from primary kraft pulp. Brown kraftliner carries code 00, arrives sized, and typically runs 25 to 45 grams per square metre on the COBB test. Testliner is the recovered-fibre family, and the list defines a brown testliner plainly as a recycled fibre based paper. It splits into four numbered grades. ## What the List Actually Requires Two properties carry most of the grading. Burst index comes from one of two ISO methods, and SCT-CD index measures compressive strength across the machine direction. | Grade | Code | Fibre | Burst floor | SCT-CD floor | | --- | --- | --- | --- | --- | | Kraftliner, brown | 00 | Primary kraft | 3.5 under 250 g/m² | 18.0 | | Kraftliner, white | 02, 04, 06 | Primary kraft | 3.7 | 18.5 | | High performance recycled | 89 | Recovered fibre | 2.8 | 19.0 | | Kraft top liner, brown | 90 | Recycled, virgin top | 2.8 | 14.5 | | Testliner 1 | 10, 11, 12 | Recovered fibre | 2.8 | — | | Testliner 2 | 20, 21, 22 | Recovered fibre | 2.2 | — | | Testliner 4 | 38 | Recovered fibre | 1.3 | 11.5 | Those burst floors are index values rather than raw pressures, and the figure shifts with the method. Kraftliner below 250 grams per square metre needs 3.5 under one ISO method or 3.6 under the other. Substance moves the testliner floors as well. Testliner 1 needs 2.8 or 3.0 below 200 grams per square metre, and 2.8 or 2.9 above it, so one grade name sets two bars. A grade threshold means nothing without the corrugated basis weight it applies at, so the two belong on the same line of a specification. Burst itself is one of the two historic routes to certifying a box, and the reference on ECT vs Mullen covers what that property does and does not predict. ## The Categories Overlap Here is where the simple story fails, because the same list contains a brown high performance recycled liner, code 89, built from recovered fibre. Its compressive floor is 19.0 on the SCT-CD index. Kraftliner's floor is 18.0 below 250 grams per square metre, and 18.5 for the uncoated white grades. > Figure: On compressive strength the ranking inverts, so the fibre basis alone does not sort the papers. So a buyer can specify a recovered-fibre grade above a primary-fibre one on the property that governs stacking. Anyone buying on the word recycled is sorting the list by the wrong column. Brown kraft top liner, code 90, blurs the line further: a recycled base under a top layer predominantly made from virgin wood pulp. The medium side splits the same way, with primary-fibre semi chemical fluting sitting beside recycled medium grades that run from an SCT-CD floor of 19.0 down to 13.5. The reference on corrugated flute types covers what the profile itself contributes. ## A Grade Is a Floor, and It Promotes Itself One rule in the list changes how every grade name should be read. A testliner that exceeds the burst or SCT-CD limit for its grade moves into the next superior grade. A paper falling below both limits does not qualify as testliner at all. So the grades are floors with automatic promotion, not bands. A sheet sold as Testliner 2 sits between its own floor and the Testliner 1 floor, with nothing in the name saying where. Two honest Testliner 1 sheets can therefore differ, one barely clearing 2.8 and the other just short of the grade above. Both labels are correct. Which is why a grade name alone cannot support a performance argument, and why the measured values are what to ask for. ## What to Put on the Specification The fibre story is worth one honest paragraph. Every page reached asserts that virgin fibres run longer and bond better, and that repulping shortens them, and none of them measures it. The figures on offer come from manufacturers' own pages with no test standard cited. What is specifiable sits in the grade list. Name the grade code, the property floor you need, and the ISO method behind it. That trio is enforceable where a fibre description is not. One scope note matters. The list is European and references ISO methods, while North American specifications run in pounds per thousand square feet. Then confirm it on the finished container. The box compression test is where a liner choice finally shows up, and a grade floor predicts that only loosely. ## Common Questions ### Is kraftliner always stronger than testliner? Not on every property. Kraftliner's burst floors are higher, but one recovered-fibre grade in the same list carries an SCT-CD compressive floor of 19.0 against kraftliner's 18.0. On the property that governs stacking, that recycled grade sits higher. ### What do the testliner numbers mean? They identify grades with descending property floors. Testliner 1 needs a burst index of at least 2.8, Testliner 2 at least 2.2, and Testliner 4 at least 1.3 with an SCT-CD index of 11.5. ### Can a paper move between testliner grades? Yes, and the list requires it. A testliner exceeding the burst or SCT-CD limit for its grade moves up one grade, and a paper below both limits does not qualify. So two correctly labelled sheets of one grade can differ. ### How much strength does recycled content cost? No reachable source measures it. The fibre-length account is asserted everywhere and quantified nowhere, and the figures circulating come from manufacturers' own marketing with no test method attached. Compare grade floors and measured values instead. **How to weigh this page.** Every grade code and property floor comes from the published European list of base papers, sixth edition, in the publisher's own copy. Parts of that document's tables were not legible in the form reached. The breakdown for one testliner grade is therefore left out rather than guessed, and only figures stated plainly appear above. The list is European and uses ISO methods, so it does not map directly onto North American conventions. **Key takeaways** - Kraftliner and testliner are grade names in a published list, each carrying a code and minimum measured properties rather than describing a material. - A brown high performance recycled liner has an SCT-CD floor of 19.0 against kraftliner's 18.0, so the categories overlap on compressive strength. - Brown kraft top liner blurs the line further, pairing a recycled base with a top layer predominantly made from virgin wood pulp. - Grades are floors with automatic promotion: beat the burst or SCT-CD limit and the paper moves up one grade. - The fibre-length account is asserted everywhere and measured nowhere, so specify the grade code, the property floor and the ISO method instead.