How did a brown sheet of paper conquer the world?

Created on 05.16

The word "kraft" comes from the German "Kraftpapier" — meaning strength, force, power. It is an apt name. The defining quality of kraft paper has never been its appearance or its sheen; it is the raw, inherent toughness that comes from how it is made. And yet, on the strength of exactly that quality, kraft paper has stood at the centre of the global packaging industry for over a century, and remains the material of choice for countless brands and manufacturers today.

Pick up a sheet of kraft paper and the difference from ordinary paper is immediately tangible. The fibre structure is present in the hand — substantial, honest, resistant to tearing, resistant to folding failure. That feel is not incidental. It is the direct result of the sulphate pulping process, which preserves the long cellulose fibres in wood to the greatest possible extent, and those long fibres are the foundation of everything kraft paper is known for.

Why is kraft paper so strong?

Kraft paper is produced using the sulphate (kraft) pulping process, which minimises degradation of the cellulose molecular chains during cooking, preserving a high proportion of long fibres in the finished sheet. The result is a paper with tensile strength, tear resistance, and burst resistance that consistently outperforms most other paper grades at equivalent grammage. Put simply: kraft paper is harder to tear, harder to puncture, and more load-bearing than the majority of papers it sits alongside on a specification sheet.

This structural advantage makes kraft paper the natural first choice wherever packaging must withstand mechanical stress — from the transport of construction materials and chemical raw materials, to the shopping bag that carries a consumer's groceries home.

Three primary applications: bags, boxes, and cartons

From the packaging industry's perspective, kraft paper divides naturally into three principal application categories, each with its own performance requirements and product forms.

The first is bag-making. Kraft paper bags are strong, have good cushioning properties, and can carry substantial weight without failure — delivering a more reliable experience for the end user. Common applications include retail shopping bags, food packaging bags, and industrial sacks for materials such as fertiliser and cement. Whether the destination is a luxury boutique or a roadside stall, kraft paper's strength makes it the default choice for paper bag production.

The second is box-making. Kraft paper cartons and boxes take an enormous variety of forms, and can be customised to suit almost any brand or product requirement. Bakery boxes, premium gift boxes, printed retail cartons — kraft paper's natural, unpretentious texture communicates an authenticity that plain white board often cannot. In a market where consumers are increasingly fatigued by polished, generic packaging, the unembellished quality of kraft paper has a genuine and growing appeal.

The third is corrugated board and shipping carton production — the most visible application in everyday life. Corrugated boxes are typically constructed with kraft paper as the liner and medium, with multiple plies combining to deliver excellent compression and impact resistance. Removal boxes, e-commerce shipping cartons, beverage cases — the packaging that takes the most punishment in transit owes its performance directly to the kraft paper inside it.

It is worth noting that kraft paper is both biodegradable and recyclable, with a significantly lower environmental impact than plastic or composite packaging materials. At a time when sustainable packaging has moved from aspiration to expectation across most markets, this is not a minor point — it is one of the most compelling reasons a growing number of brands are actively choosing kraft paper, and one that is increasingly reflected in procurement decisions at every level of the supply chain.

How to assess kraft paper quality

A thorough quality assessment of kraft paper covers six key parameters: thickness, density, smoothness, elongation, burst strength, and whiteness. Precise measurement of each requires dedicated testing instruments, and a complete set of test data is the most reliable basis for a sourcing decision.

In practice, however, there is a straightforward field test that experienced buyers use as a first-pass check: fold the paper repeatedly by hand and observe the crease lines. Kraft paper is a long-fibre paper with inherently high resistance to fracture and fold failure. On a quality sheet, repeated folding should produce only faint crease lines with no significant cracking. If visible cracks or breaks appear after only one or two folds, it is a reliable indicator that the fibre quality is below standard and the paper will not perform as expected under normal use conditions.