What Is Kraft Paper and Why Is It a Popular Packaging Material?

What Exactly Is Kraft Paper?

Kraft paper is a high-strength packaging paper made from wood pulp through a chemical process known as the kraft process. The word “kraft” comes from the German word for “strong”—and strength is precisely what defines this remarkable material.

Natural or unbleached kraft paper has a characteristic light brown colour, while bleached kraft paper is white. Natural kraft paper is the strongest of the common packaging papers and is used when maximum strength is required. It is a versatile material that can be coated or laminated to improve its barrier properties and provide additional strength.

Kraft paper typically has a basis weight ranging from 18 to 200 lbs (approximately 8.2 to 90.7 kg), with common weights falling between 25 and 80 lbs. It is available in various forms, including natural brown, unbleached, heavy-duty, and bleached white.

How Is Kraft Paper Made?

The manufacturing process behind kraft paper is what gives it its exceptional strength and durability. The kraft process—also known as the sulphate process—was invented in Germany during the 19th century and has been refined over the years to create a strong, durable paper product

Step 1: Preparing the Wood Pulp

To make kraft paper, softwood needs to be converted into virgin wood pulp—almost pure cellulose fibres—via the kraft process. The process begins with wood chips, which are placed in a hot mixture of water, sodium hydroxide, and sodium sulphite, called “white liquor”.

Step 2: Breaking Down the Wood Components

This chemical solution breaks the bonds that link lignin to the cellulose. The result is a separation of the two main components of wood—lignin and cellulose—leaving a solid wood pulp and a “black liquor”. The pulp is cooked, or digested, at high temperatures—around 170°C (338°F)—for approximately three hours until most of the lignin is solubilised.

Step 3: Washing and Forming

The pulp undergoes several screening processes where larger pieces are removed. The liquid is drained off and the pulp is washed to remove the chemicals. The wood pulp is then washed before being formed into the final thickness of paper desired.

Because of how the kraft process works, more wood fibres are preserved during the breakdown process, resulting in a stronger, darker, and more resistant paper than other paper forms. The process produces especially strong, unbleached papers that can be used directly for bags and other packaging applications

Kraft Paper vs. Conventional Paper

While kraft paper and regular paper may look similar at first glance, they are fundamentally different materials with distinct properties and purposes.

Strength and Durability

Kraft paper is significantly more durable than regular paper due to its stronger fibres, higher tear resistance, and manufacturing process. Regular paper is delicate in nature and can tear easily. Kraft paper has up to four times higher tear resistance compared to standard office paper or low-grade recycled paper.

Regular paper crumples easily. Kraft resists. This makes kraft paper ideal for packaging applications that require strength and reliability.

Appearance

Regular paper is typically white, bright, and smooth, making it ideal for printing documents and colourful designs. Kraft paper, on the other hand, has a thick texture and a brown shade, giving it a rustic and natural look. This earthy aesthetic appeals to brands that want to highlight eco-friendly values.

Production Process

Regular paper undergoes more bleaching and refining, making it smoother and lighter but less durable. Kraft paper passes through a minimal bleaching process and can retain most of its natural fibres, which gives it a natural look. The use of fewer chemicals minimises waste, making it a more sustainable choice.

Cost

Regular paper is generally less expensive for production and purchase. However, kraft paper provides better value for packaging due to its strength and other benefits. The reduced need for additional protective materials often offsets the slightly higher initial cost.

How Is Kraft Paper Used in Packaging?

Kraft paper’s versatility makes it suitable for a wide range of packaging applications across industries.

Shopping bags that can handle heavy groceries or fashion articles are commonly made from kraft paper. Its strength and tear resistance make it ideal for carrying heavy loads without breaking.

Corrugated boxes are made with kraft liner—kraft paper used as the outer and intermediate plies of corrugated board. Kraftliner provides exceptional strength and moisture resistance.

Wrapping products and gifts is another common use. Kraft paper is more resistant to punctures and tears than regular paper, making it a great choice for wrapping.

Void fill is an important application. Since the kraft process preserves a higher level of wood fibres, kraft paper has greater shock absorbency than standard paper, making it a great void filler.

Industrial and consumer packaging applications include form-fill-and-seal (FFS) packaging used for sharp-edged or heavy items such as toys, dry food, spare parts, and building materials.

Mailer bags and e-commerce packaging are increasingly using kraft paper for its robust protection and puncture resistance.

Food packaging is another major application. Kraft paper is suitable for non-food and food applications with direct food contact certifications. It is used to package flour, sugar, dried fruits and vegetables, snacks, coffee, and tea

Common Types of Kraft Paper

There are several distinct types of kraft paper and paperboard, each designed for specific applications.

Coated Unbleached Kraft (CUK)

CUK is a strong, durable board featuring a white coated surface on one side and a kraft brown back. It combines the strength of unbleached kraft fibres with a printable white surface. CUK is often used in beverage carriers and frozen food packaging because of its wet strength. It is one of three major types of paperboard used for consumer goods.

Solid Bleached Kraft (SBS)

SBS is a premium white board made from 100% chemical pulp, ideal for high-end printing. Bleached kraft paper is the strongest white paper and is used where strength, printability, and appearance are important. Bleached kraft fibres are also used in the production of solid bleached sulphate (SBS), a high-quality paperboard.

Coated Recycled Board (CRB)

CRB is an economical board made from recycled fibres. It is made from 100% recovered paper and usually contains a minimum of 35% postconsumer materials. CRB is a cost-competitive packaging option with significantly lower environmental impacts than virgin board.

Key Benefits of Kraft Paper

Kraft paper offers a compelling combination of benefits that make it a preferred choice for packaging across industries.

Exceptional strength and durability are the hallmarks of kraft paper. It offers superior strength, durability, and puncture resistance. Natural kraft is the strongest of all paper types.

Lightweight properties make kraft paper ideal for high-volume shipping. Despite its strength, kraft paper is an incredibly lightweight packaging material.

High puncture resistance protects products during filling, handling, and transit. The inherent fibre strength makes it possible to use less material, helping to cut packaging weight and cost.

Cost-effectiveness is another advantage. Kraft paper is incredibly cost-effective, especially when purchased in bulk.

Excellent printability is a key benefit. Some kraft papers feature a smooth surface that delivers superior printability—a clear advantage over natural brown papers with rougher surface textures. Printing options include CMYK or Pantone printing with matte or gloss lamination, hot stamping, embossing, and UV coating.

Versatility makes kraft paper suitable for multipurpose packaging across food, retail, and flexible applications. It ensures excellent runnability in complex packaging material production processes.

Kraft Paper Customization Options

Despite its natural, rustic appearance, kraft paper offers extensive customization possibilities for brands.

Printing options include flexographic, offset, and digital printing. Custom CMYK or Pantone printing is available.

Surface finishes can be applied to achieve different looks and feels. Options include matte or gloss lamination, foil stamping, spot UV, embossing, debossing, and UV coating. Aqueous coating—a clear, fast-drying, water-based, and eco-friendly coating—is available in gloss or matte finishes. Soft-touch coating and varnish are also options.

Custom shapes can be achieved through die-cutting and creasing. This allows brands to create packaging that fits their products perfectly and reflects their unique identity.

Colour options extend beyond the traditional brown. While natural kraft is typically brown, white and black kraft papers are also available. This allows brands to select colours that match their product requirements and brand aesthetic.

Kraft Paper and Its Environmental Impact

Perhaps the most compelling reason for kraft paper's popularity is its strong environmental credentials. In an era of increasing environmental awareness, kraft paper offers a sustainable alternative to plastic and other non-renewable packaging materials.

Renewable raw materials are the foundation of kraft paper. It is made from wood pulp sourced from sustainably managed forests. Kraft paper can be made with many types of wood, including resinous pines or bamboos, which are traditionally left out by the paper-making industry.

Recyclability is a key advantage. Kraft paper is 100% recyclable and biodegradable. It can be recycled easily and will eventually degrade under the right circumstances. According to a study, paper-based packaging can be recycled more than 25 times.

Biodegradability means kraft paper breaks down naturally in the environment. It is fully recyclable and biodegradable, making it an environmentally responsible choice.

Lower environmental impact compared to alternatives is well documented. A life cycle assessment found that kraft paper pallet wrapping has a significantly lower environmental impact compared to both virgin and recycled-content plastic stretch films, particularly in categories such as climate change and fossil resource use.

Reduced chemical usage is another environmental benefit. Nearly no chemicals are used during the production process, and all chemicals used can be removed or reused. Kraft paper requires less freshwater to produce than many other packaging and paper products.

Carbon footprint is increasingly being addressed by manufacturers. Some kraft papers are now produced as "CO₂-neutral," using only renewable energy sources.

Certifications provide assurance of sustainable sourcing. Many kraft papers are produced in FSC® and PEFC certified mills. These certifications support circular economy principles and enable retailers to reduce their environmental impact.

Conclusion

Kraft paper has earned its place as one of the most popular packaging materials in the world. Its unique combination of exceptional strength, versatility, and environmental sustainability makes it an ideal choice for brands across industries.

From its origins in the 19th-century kraft process to its modern applications in e-commerce, retail, and food packaging, kraft paper has proven its value time and again. It offers the strength to protect products during transit, the printability to showcase brand identity, and the eco-friendly credentials that today's consumers demand.

Whether you are shipping heavy industrial goods, wrapping delicate gifts, or packaging premium food products, kraft paper provides a reliable, sustainable, and cost-effective solution. As brands continue to seek ways to reduce their environmental impact without compromising on quality, kraft paper will undoubtedly remain a cornerstone of the packaging industry for years to come.