Packaging Reference Library · Technical Reference

Kraft vs White vs Recycled Liners

Linerboard comes in brown kraft, white and recycled grades. This sheet explains how each is made, how it looks and prints, and when each is the right choice.

Ref PK-0104ASTM D4727

Draft, open for review. Check every value against the governing standard and the manufacturer’s data before use.

What it is

Linerboard is the flat paper on the faces of corrugated board. Virgin kraft liner is made mainly from new softwood pulp by the kraft process. It has long fibers and is strong for its weight. Recycled liner, sometimes called test liner, is made mainly from old corrugated containers and other recovered paper. Its fibers are shorter, so a heavier sheet may be needed for the same strength. White liners have a white surface, made by bleaching the pulp, by adding a white top layer, or by coating. Mottled white has a white top layer with some brown showing through. ASTM D4727 covers terms and grades for corrugated board stock.

How to identify

Look at the outside and the cut edge. Brown kraft is uniform brown. Recycled liner is often a slightly duller or grayer brown, and may show small specks. Mottled white is white with a cloudy, uneven tone. Bleached white is bright and even. Clay-coated white has a smooth, slightly glossy surface. The inside liner is often brown even when the outside is white.

Liner grades

Liner type	Look	Print surface	Typical use
Virgin kraft	Uniform brown	Good for one- and two-color flexo	General shipping, heavy loads, wet or cold conditions
Recycled (test liner)	Duller brown, may show specks	Similar to kraft; varies	General shipping where cost and recycled content matter
Mottled white	White with cloudy tone	Better contrast than kraft	Branded shipping boxes, moderate graphics
Bleached white	Bright, even white	Good for multi-color flexo	Retail-ready and branded boxes
Clay-coated white	Smooth, bright, slightly glossy	Best for high-quality flexo and litho	Retail displays, premium mailers
Litho-laminated	Printed paper sheet glued to corrugated	Photo-quality	Retail packaging and point-of-sale displays

Key points

White and coated liners cost more and may scuff or show dirt in rough handling.
Recycled content is a sustainability selling point. Strength still has to be checked on the box maker's certificate.
Virgin kraft generally holds strength better in high humidity, but the right test is the board grade, not the color.
Printing method matters. Flexographic printing goes directly on the liner. Litho printing goes on a separate sheet that is laminated on.
Liner choice does not change the box style or flute. Put liner, flute and strength grade together on the spec.

Common mistakes

Assuming brown always means virgin kraft.
Assuming recycled liner cannot meet the strength needed.
Specifying white liner without saying which white.
Expecting photo-quality graphics on uncoated kraft.

Governing standards: ASTM D4727 (corrugated and solid fiberboard sheet stock); box maker's certificate for strength grade.

Reference only. Verify against the current governing code or standard, the manufacturer's data and the project documents before use. Apps for Distributors disclaims liability arising from reliance on this reference.

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