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Kraft Packaging Store October 22nd , 2021 · 16 min

What Is The Properties Of Kraft Paper?

Kraft paper is an environmentally friendly, recyclable, and cost-effective material often used to create sustainable packaging products such as bags and boxes. Due to its many benefits, individual consumers and larger-scale companies alike have come to prefer Kraft paper as their packaging material of choice, especially for shipping long distances or even internationally. Kraft paper is lightweight and can travel swiftly at a low cost as it does not need to go through additional testing to pass customs.

Excellent Kraft paper


Durability of Kraft paper

Despite being a form of paper, Kraft paper is created using a process of corrugation and layering that strengthens the material into something much stronger and sturdier than other forms of paper. Through this procedure, Kraft paper becomes a high-performing and durable packaging material. This makes it ideal for shipping, as it is resilient to the wear and tear associated with traveling long distances. Kraft paper is even suitable for industrial, heavy-duty uses, as it can withstand many climates and environments and can be crafted to support and carry heavy items. Kraft paper can even be treated to make it moisture-proof or fully waterproof and greaseproof to prevent damage from leakage or spills. For example, Kraft paper packaging can be used for cement bags, fertilizer bags, and other heavy-weight and precarious materials. An added benefit is that, although Kraft paper packaging can be incredibly strong, it still retains a certain degree of breathability, which is important for some products.

In addition, Kraft paper is impervious to the dangers of freezing and can stand up to higher temperatures, unlike glass and plastic which are susceptible to cracking and breaking in extreme climates or when undergoing quick transitions from hot to cold or vice versa. Yet, Kraft paper is more cost-effective than these other types of packaging, despite being more durable. These qualities, and the fact that the material can easily be made to fit food-grade requirements and certifications, make Kraft paper packaging a great option for the foodservice industry, such as restaurants and caterers.

Food-grade Kraft paper for food packaging

Kraft paper is also available in food-grade variations, which is popular for restaurants, catering businesses, food delivery services, and other similar companies. These boxes are a great, sustainable alternative to the commonly used plastic or styrofoam to-go containers.

Although these containers are recyclable and environmentally friendly, they are durable enough to keep foods fresh and protected for a long time. We offer sturdy, heavy-duty varieties of Kraft paper packaging that ensures food will arrive safely into the consumers hands, whether it’s traveling across town or just across the counter. We even provide packaging with a superior moisture-proof and waterproof coating, as well as a greaseproof coating to support the integrity of the box from within and without. Unlike other paper-based packaging that often quickly disintegrates, this laminate allows our packaging to remain strong in any situation. Both our anti-oil Kraft bags and various other types of boxes and containers come in a plethora of sizes to fit every food vendor’s needs.

Kraft paper food packaging

Until more recently, there was little documentation, testing, and transparency required for manufacturers to pass food safety requirements for their Kraft packaging products. Consumers and businesses did not have access to the full details of their manufacturer’s codes, standards, or practices to ensure the quality or integrity of their packaging for their custom orders, especially as many bought from countries abroad.

Now, new requirements have been put in place to make this process more thorough and reliable. Packaging must pass certain tests and manufacturers must present testing reports to the country of delivery when exporting. For example, documentation must be provided for packaging entering the United States to verify the quality and safety based on FDA reports. Many manufacturers have not been able to fulfill these requests and present compliance.

One of the materials these tests look for is optical brightening agents, or fluorescent whitening agents (FWAs), which may be detrimental to human health in high doses and can pollute the environment as they are not biodegradable. With long-term exposure, these brightening agents may even increase the risk of cancer. These substances are often added to Kraft paper to make it brighter and whiter. Because Kraft paper is naturally brown in color, large quantities of this agent must often be added to achieve the hue and purity of white many consumers are looking for and which manufacturers commonly produce.

The FDA limits brightening agents in the US, but there are ways to look for these substances and find whether there is a high or low dose in your paper. There are three main ways of testing Kraft paper at home:

  1. A currency detector can be used to quickly and easily show whether Kraft paper is safe to use. If there is too much phosphor in the paper, the UV light in the detector, when swept slowly over the surface of the paper, will produce a fluorescent glow-like effect. The brighter the effect, the higher the level of brightening agents.
  2. If you don’t have a detector, you can also try using the ultraviolet light of the sun. This is not as accurate as using a detector and will not pick up on smaller quantities in the paper. If there appears to be a fluorescent effect while holding up the paper to the sunlight, there is likely a large quantity of brightening agents in the paper. However, in some cases, even higher quantities will not create a fluorescent effect in the sunlight. So it is not a trusted method.
  3. Even looking at Kraft paper with the naked eye can reveal a lot about what it contains. If the whiteness of the paper seems pure, it is likely that large quantities of fluorescent substances have been added. If there is a natural yellowness or off-white color to the paper, it is likely that lower doses were added. As a general rule, if the Kraft paper is as bright as copy paper, the dose of brighteners used in the paper is too high to be safe for use with food. This is why natural and untreated brown Kraft paper is best for the food industry.

White Kraft Paper

Color classification of Kraft paper

  1. Natural Kraft paper is a light brown color often speckled with impurities and has a slightly rough texture. This is because the paper is made from wood pulp, a natural material, and has not been treated with unnatural chemicals to make it brighter or whiter.
  2. Kraft paper can also be made with a ‘finished’ or smooth side and a natural or rougher side. This leaves one half of the paper unprocessed while coating the other to create a brighter, more resilient surface that is slightly more yellow in color and a texture more suitable for printing purposes. However, there will still be impurities on both sides.
  3. Double-sided smooth Kraft paper maintains the natural look of plain Kraft paper but makes it smoother and brighter with a coating. There is usually still a brown-yellow color to the Kraft paper but the lesser texture allows for it to be colored or printed on both sides and makes it slightly more durable.
  4. White Kraft paper comes in several varieties. There are white and ultra-white, or high-white variations, which each refer to the different purities or shades of whiteness. White Kraft paper can also be made to withstand high humidity or even be flame-retardant and waterproof. The texture and color allows the white paper to be completely printed, dyed, colored, or otherwise embellished and embossed in almost any way. However, it is not safe for food contact due to the brightening agents used to whiten the paper.
  5. Yellow Kraft paper also comes in two different shades: The first is a one-sided bright-yellow, a refined variety of yellow Kraft paper. The other is a double-sided yellow Kraft paper with stripes. Both are quite high-end, high-grade, and more expensive than natural Kraft paper and are easier to print on.
  6. There are also several varieties of black Kraft paper, which come in different weights and hues. This includes gray-bottom single black cardboard, darker single-sided transmittance cardboard, darker double-sided transmittance cardboard, all-wood paddle black cardboard, and more.

This style of Kraft paper is suitable for photo albums, photo frames, gift boxes, jewelry boxes, shoe boxes, stationery, notebooks, packaging for handmade items, and more. You can see examples and learn more about how different Kraft papers are used for various box styles in this article on the Top 10 Eco Friendly Kraft Boxes Types List.

Kraft paper color differences caused in production

Kraft paper is made with a mixture of natural and recycled wood pulp. Because of this, the paper usually has a natural brown color and contains impurities including uneven hues and textures.

The wood pulp used to create Kraft paper often comes from multiple sources. Just like the variety of grains and textures that can be found in wood, this causes a mixture of shades of browns and tan However, the difference in hue is largely minimal and will not be startling from batch to batch. Furthermore, despite the differences in wood materials we use, we are able to achieve 99% consistency with our Kraft paper coloring thanks to our mixing and production process, allowing us to keep our packaging as uniform as possible for our customers.

The Color of Kraft paper

The difference between white Kraft paper and brown Kraft paper

Kraft paper comes in two main colors: white and brown. Brown is the standard, natural variety of Kraft paper while white Kraft paper is usually used for printing purposes, as designs and colors will be bolder and clearer on a pure white background. In addition to color, brown and white Kraft paper are very different when it comes to the processes used to create them and the materials used. While brown Kraft paper is made of natural wood pulp, white Kraft paper is made of bleached wood pulp. Brown Kraft paper is often used for packaging such as to create boxes and bags, while white Kraft paper is often used for printing, such as in a paper form. Still, white Kraft paper is a good alternative to virgin white paper products, as it is more cost-effective and sustainable.

Brown Kraft paper

Eco-friendly recycled Kraft paper

Both types of Kraft paper are created from wood pulp harvested from forest farms, which are closely monitored to regrow more quickly than natural forests. This ensures that the materials will not be overharvested and will not contribute to deforestation or other environmental dangers. This also allows the wood materials to be better and more easily recycled.

Kraft paper is not only made of sustainably sourced raw materials (natural wood pulp) but it can be recycled and reused. In fact, Kraft paper can be recycled not just once, but twice, to minimize the use of raw materials even further. This makes Kraft paper packaging much more environmentally friendly than other forms of packaging materials, especially those made of styrofoam or plastic which pollute our earth and do not decompose for hundreds of years. Raw materials are usually used to create higher grade Kraft paper that is safer for creating food-grade materials, whereas recycled materials are usually utilized for standard packaging and paper.

Not only is wood pulp a naturally inexpensive raw material, but the ability to recycle Kraft paper makes the production process even cheaper, cutting costs on the final packaging materials and making Kraft paper more affordable than other alternatives.

Although Kraft paper is often made of recycled materials, it is still of high quality. There are several levels of Kraft paper quality which are based on the materials used, production process, and end result: excellent, A class, and three ordinary levels.

Eco-friendly Recycled Kraft paper

Weight and thickness of Kraft paper

The weight of Kraft paper merely refers to the heaviness of the paper or grams of weight per square meter. This is also called the gram weight or gsm (grams per square meter) of the paper. This measurement helps manufacturers understand where to cut the paper.

The weight of Kraft paper can be measured with an instrument called a cliper to gauge the micrometer of the paper. The weight can also be estimated by feeling the paper with your fingers to see how thick it is. For the most part, those who do not create Kraft paper will only be able to tell generally what the weight or thickness of the paper is.

The weight itself will not matter much to consumers, but in general, the heavier the paper is, the thicker it will be. However, this thickness is a matter of preference and does not correspond with quality. That being said, some thicknesses may be better suited for particular purposes. For example, thicker Kraft paper is usually more sturdy and durable than thinner Kraft paper. Because of this, some industries or businesses may request thicker or thinner varieties for their packaging based on the look and feel they desire.

The thickness of the Kraft paper can affect the end result depending on other embellishments and needs. Thinner paper is not ideal for printing as it is not as smooth, showing textural imperfections more easily and inevitably creating a sub-par print. In some cases, this thinner Kraft paper can even be detrimental to the printing plant to use as it can slow down production. In fact, printing on thin paper can reduce a production plant’s speed from 14,000 sheets per hour to 10,000 sheets per hour, or a 30% decrease in efficiency.

That is why choosing a thickness of paper that is suitable for your particular project and needs is crucial for an efficient process and high-quality end result. If you’re looking to print on your Kraft paper, make sure to pick a suitable thickness.

gram weight of Kraft paper

Personalization of Kraft paper

Customers eat with their eyes before they eat with their stomachs. When they first walk into a shop and aren’t familiar with any of the products or what they will taste like, they are likely to choose the packaging that looks the most appealing. This is why having packaging that is beautiful is as important as having packaging that is functional and durable. Kraft paper packaging is the best of both worlds as it can be easily printed on and personalized in order to provide marketing opportunities and better branding for companies, allowing you to add logos, artwork, ingredients, product information, and more to your food packaging boxes and bags to catch customers’ attention.

With so many other similar products on the market and so much competition, it’s important to stand out to engage customers no matter what you’re selling. This is why having packaging that will stand out on store shelves can be so important for sales. This can be done by adding colors, designs, logos, artwork, and other fun embellishments to your boxes and bags to make them more intriguing and unique, prompting consumers to buy. At first glance, a customer should be able to tell what your product is and what makes it better than others, which can be done in a multitude of visual and textual ways.

Kraft food packaging

What kind of Kraft paper is better for printing?

The requirements for printing will depend on the specifics of the design and the printing plant. Some printing needs may require thicker or higher quality paper to get the best quality image and legibility.

For the best printing results, Kraft paper should be as smooth and high quality as possible. It should be inspected for stains, holes, creases, cracks, fiber groups, and other impurities and textures that could disrupt the ink’s application.

Having an understanding of not only the appearance of the paper but its actual specifications in terms of quality can also be helpful. For example, the paper’s chemical properties can affect its absorption rate and, thereby, the dispersal of ink across the page. This is especially important if you’re looking to have your Kraft paper colored, as this can affect the final hue, transparency, and uniformity of the resulting color. The water content of Kraft paper is also an important consideration. The higher the water content of Kraft paper, the most likely it will be to wrinkle while printing.

Printing Kraft paper

What paper does a Kraft notebook usually use?

Standard notebook pages usually use Kraft paper that is between 400 and 500 grams per square meter for the cover and inner pages with a weight of 70 to 80 grams per square meter. However, because of the way this paper can be used, the thickness and weight can be even lower while still producing a great result. The minimum for a notebook should be between 400 and 450 grams per square meter for the cover and 50 to 70 grams per square meter for the paper inside. What you decide on within that range depends on what qualities and thickness you want the notebook to have or what it will be used for.

Notebooks usually use standard Kraft brown paper for the outer cover, which is treated to be more durable and darker in color. The inner pages, as a result, will appear smoother and lighter in color than these outer pages, which makes them more suitable for writing. Other types of Kraft paper used in notebooks include white Kraft paper, American Bull card, refined Kraft paper, and other writing papers.

Kraft paper notebook

Use Kraft paper to make printed brand brochures

Brochures are commonly made with art or craft paper, which is not an environmentally friendly material. This is especially unfortunate for those marketing for sustainable organizations or about environmental issues. Kraft paper, which is made of wood pulp and recycled and recyclable materials, is a much more sustainable resource for creating brochures and has begun to become a more popular product for use in the industry. Not only is Kraft paper made of raw, natural materials from sustainable, man-made forests, but it can be recycled and reused multiple times to reduce the environmental impact of its production. This is also important for companies in the US and Europe, where environmental protection is a highly relevant matter of concern among the population, and laws and regulations have been put in place to ensure the sustainability of certain products.

In addition to its environmental benefits, Kraft paper can be easily printed in the color or colors of your choice. The natural texture of the Kraft paper beneath will create an elegant, unique effect and feeling to the brochures that will give them a subtle, yet fascinating character and set them apart from other similar brochures made of craft paper.

Brochures made of Kraft paper can also be easily customized, allowing the paper to fit the size, thickness, and other desired qualities for the project or business. It can also be printed in a multitude of ways with colors, text, images, or artwork to suit any company or need.

Personalised Kraft Guest Book


Kraft paper made of Bamboo pulp

In recent years, bamboo pulp has emerged as an alternative material to other wood pulps for use in refined Kraft paper products. This type of Kraft paper is similar to the standard variety but does have some differences in texture and suitable uses.

Bamboo has become a popular material for Kraft paper as it is such a sustainable resource. Bamboo grows more quickly than most other trees, allowing the resource to be replenished more easily and efficiently.

Bamboo is also a softer wood, which creates a final Kraft paper product that is flatter and more delicate than Kraft paper products made of other wood pulps, giving it a different feel and texture. However, because of this, bamboo also creates Kraft paper that is less durable, less hard, thinner, and lighter weight than Kraft paper made of other types of wood pulp. This limits the use of bamboo pulp Kraft paper and makes it less suitable for heavy-duty use. However, with a smoother texture and better, more uniform color, Kraft paper made from bamboo pulp is great for high-end packaging of small items, such as jewelry, and for high-quality notebooks.

Bamboo pulp Kraft paper

Characteristics and applications of coated Kraft paper

Coated Kraft paper is often used for printing purposes. This variation of Kraft paper smooths the naturally textured surface caused by the wood pulp of Kraft paper to create a more uniform surface. This allows inks to adhere more evenly and efficiently to the paper. Kraft paper can either be coated on one side or both sides depending on the project. This can allow for packaging to be printed on the outside and inside if so desired.

Coated Kraft paper has the added benefit of having high compression resistance, meaning that it is more durable than plain Kraft paper and will resist damage such as tears and rips. In fact, a more durable and thicker version of coated Kraft paper can even be used in place of other corrugated cardboard to hold and carry heavy-duty items such as appliances. Likewise, auto parts and other products are often kept safely inside this thick Kraft paper protection, which can be made moisture-proof and which has anti-freezing properties to protect products from climactic damages during transport. Because of these qualities, it can even be used for frozen or refrigerated goods.

Although coated Kraft paper is better for printing purposes, it also takes longer to dry, as the layer of coating slows down the absorption rate of the ink into the wood pulp layer. This process only takes about 20 seconds but will make the printing process of large quantities of coated Kraft paper much slower and increases the risk of smudging or printing problems. Yet, when done correctly and carefully, the result can be more brilliant and pronounced than if it were to be on standard Kraft.

coated Kraft paper


Electrostatic phenomenon during Kraft paper printing

On occasion, the dryness and friction of Kraft paper during the printing process will cause static electricity to build up, especially in dry climates or weather. This can cause delays in the printing process and create issues with the printing machines.

During the printing process, Kraft paper is fed onto a conveyer belt that transports the paper through the printing machines and separates the sheets into piles. The movement of the paper against the belt, the machine, and against other pieces of paper creates friction during nearly every step of the process. Over time, the electricity from this friction gathers on the Kraft paper, which attracts any hair and dust in the vicinity. This can also create issues if the charged Kraft paper comes into contact with another piece of paper with a polar charge, creating printing errors or causing the pages to stick together and be missed.

To limit this electricity, a high-voltage, high-frequency electrostatic eliminator is installed into or near the drum to prevent issues and disperse extra static. This charge can also be limited by improving the conditions within the shop, such as by increasing the humidity. Friction does not occur as regularly when there is more moisture in the environment, it is only a problem in dry conditions, so making a more humid environment will limit such issues. In most cases, if the humidity in the printing environment is less than 40%, friction will increase and cause static. Increasing the humidity can be as easy as sprinkling water or having cups of water near the printing machines but not so close that it will damage the paper or the machines, of course. You can also use a humidifier to increase the humidity in the printing shop or a humidification treatment can be applied to the Kraft paper itself to increase the water content and prevent static electricity.

If the static during the printing process becomes too intense, the paper must be stacked in a more humid environment for a time to eliminate dryness. However, it must be carefully placed to avoid damage from moisture or heat.

the hardness of Kraft paper


Kraft paper and tension

The quality of Kraft paper is greatly affected by the tension used during the production process. The tension used will inevitably affect the resulting durability and strength of the paper. Kraft paper made from natural wood pulp naturally has a better tension than that made of recycled pulp, which is part of why so many manufacturers use the material in its natural form. In fact, most imported Kraft paper is made of pure wood pulp, not recycled, and will have better durability because of it. Any materials beyond wood pulp that are added to the paper during the recycling process can affect the tensions of the paper greatly. The type of wood will also be an important factor to consider. The better and more pure the wood pulp quality, the better the tension. However, the production process used can have effects on the tension of the paper as well.

The tensile force of Kraft paper

The evenness and quality of Kraft paper

With the increasing demand for raw materials, sustainable packaging, and Kraft paper products, the market has become quite difficult to navigate. There are a number of options for consumers to choose from, but little information as to what creates a quality product. Consumers often want durable packaging that will be resistant to tearing, ripping, and other damage but do not know how to seek it out. In truth, these qualities are related to the evenness of the paper.

The evenness of Kraft paper can vary due to the way the material is processed. To create Kraft paper, raw wood pulp is made into a fiber that is then pressed, formed, and dried into sheets of paper. Because paper is made of natural fibers, it is difficult to control this evenness during the production process, creating a lack of uniformity. When fibers are pulped, or crushed into smaller, softer pieces, they can be more easily and evenly distributed. Without pulping, the longer fibers more easily gather and form together, causing thicker and thinner sections to appear during the production process. This can disrupt printing and affect ink absorption and the durability of the paper in some cases. However, processes have been put in place to limit this issue and promote uniformity.

What factors affect the hardness of Kraft paper?

Despite common misconceptions, the hardness of paper is not congruent with weight. Kraft paper with the same weights can have different hardnesses. Because Kraft paper is made of wood pulp, the hardness of the paper simply depends on the solidness of the pulp. In other words, the harder the wood the pulp is made from, the harder the final product. That’s why pure wood pulp Kraft paper is usually the hardest type of Kraft paper.

This also means that Kraft paper made from recycled wood pulp is not as hard as pure wood pulp Kraft paper. This recycled paper often uses additions such as rags, bark, and other materials that soften the makeup of the material. For recycled Kraft paper, the higher the content of wood pulp, the greater the hardness. However, the type of wood used in either recycled or pure Kraft paper will also be a factor, as some types of wood are much softer than others. Because of this, it is difficult to maintain the same level of hardness across multiple batches of Kraft paper, especially for recycled types.

the weight of Kraft paper

The difference between FSC-certified Kraft paper and 100% recycled Kraft paper

FSC-certified Kraft paper and 100% recycled Kraft paper are made with different materials but are similar in their look and uses. FSC-certified paper is usually made of raw virgin wood pulp while 100% recycled Kraft paper is made from recycled pulp. This is because, in order to be FSC-certified, the materials to create the paper must be able to be traced back to their source. In the case of either type of Kraft paper, this is usually a man-made forest farm. But, because recycled Kraft paper is made from reused materials, the origins of the raw pulp can not be verified.

Both types of Kraft paper are sustainable. The recycling of Kraft paper ensures that materials are being reused and repurposed rather than being wasted. But even FSC-certified or standard Kraft paper comes from trees that are planted sustainably in closely monitored forest farms which do not contribute to deforestation. This makes both variations environmentally friendly, although FSC certification may be preferred by some consumers looking for a way to verify the origins and materials of their paper.

Now that you’ve learned all you need to know about Kraft paper, we encourage you to take a look at some of our Kraft paper products, such as our Kraft paper gift boxes and Kraft bags.