Kraft Paper in Corrugated Packaging — Strong, Natural, Reliable

What Is Kraft Paper?

Kraft paper is a strong, durable paper produced from wood pulp using the kraft process — a chemical pulping method that breaks down wood into its component fibers while preserving their length and strength. The result is a characteristically brown, unbleached paper that is among the strongest paper grades available.

In corrugated packaging, kraft paper is primarily used as linerboard — the flat outer sheets that sandwich the fluted medium in corrugated fiberboard. Its natural brown color is the reason most shipping boxes have that familiar tan appearance.

Why Kraft Paper Is So Strong

The kraft process preserves long cellulose fibers from softwood trees (primarily pine and spruce), which interlock to create a paper with exceptional tensile and tear strength. The word “kraft” itself comes from the German word for strength, and the name is well deserved.

Compared to papers made from recycled fibers or mechanical pulping processes, virgin kraft paper offers superior performance in several key areas:

• Tear resistance: Long fibers resist tearing and puncturing under rough handling conditions.
• Tensile strength: Higher resistance to stretching and breaking under load.
• Moisture resistance: Virgin kraft fibers absorb less moisture than recycled alternatives, maintaining more strength in humid conditions.
• Stiffness: Greater rigidity contributes to better stacking performance in finished boxes.

Kraft vs. Recycled Linerboard

While virgin kraft linerboard delivers the highest strength, recycled linerboard has become an important part of the corrugated supply chain. Recycled liner uses recovered paper fibers and is available in equivalent basis weights, though with somewhat different strength characteristics.

Many corrugated boxes today use a combination of kraft and recycled papers — for example, a kraft outer liner for maximum puncture resistance with a recycled inner liner and medium to reduce cost and support sustainability goals. This blended approach allows manufacturers like President Container to balance performance, cost, and environmental responsibility.

Grades of Kraft Linerboard

Kraft linerboard is available in multiple grades to suit different board grade requirements. Standard basis weights range from 26 pounds to 90 pounds per thousand square feet. Lighter grades are suitable for consumer packaging and lighter products, while heavier grades are specified for industrial applications requiring maximum durability.

Specialty kraft papers include mottled white kraft, which has a white surface coating for a premium appearance, and fully bleached white kraft for applications where a bright white exterior is required.

Kraft Paper Beyond Linerboard

While linerboard is the primary application in corrugated packaging, kraft paper is also used for wrapping, void fill, interleaving, and protective packaging. President Industrial Products stocks a variety of kraft paper products for immediate shipping to businesses that need packaging supplies on demand.