Kraft paper is strong and durable making it an ideal choice for many applications such as packaging, wrapping, and even construction. It is also recyclable and biodegradable. The type of paper you use will have a direct impact on the quality and appearance of your finished product.
As a buyer, purchase or sourcing manager, you may be tasked with procuring kraft paper. While this may seem like a straightforward task, there are a few factors to consider to ensure that you are getting the best quality kraft paper for your money.
1. Know Your Requirement
Before buying kraft paper, it is important to know what your needs are. What are you going to use the kraft paper for? Are you looking for kraft paper for packaging heavy goods or food-grade kraft paper? Or, do you need something that is moisture-resistant? If you need kraft paper for wrapping gifts, you will want to make sure it is thin enough to easily fold around the contours of the object being wrapped yet thick enough to provide adequate protection. Once you know how you are going to use the kraft paper, you can buy a product that meets your needs and doesn’t disappoint when put to use.
2. Know the Different Types of Kraft Paper
Kraft paper comes in a variety of grades, each with its own set of properties and applications.
There are two main types of kraft paper: high-strength kraft paper and medium-strength kraft paper. High-strength kraft paper is made from virgin pulp, while medium-strength kraft paper is made from recycled pulp. Kraft paper may be unbleached (brown) or bleached (white). Bleached kraft is made from 100% wood pulp that has been treated with chemicals to give it a brighter color. Depending on your needs, one type may be more suitable than the other.
The kraft paper grade you need will depend on how the paper will be used. For example, if you’re planning to use the paper for packaging, you’ll need a higher grade than if you’re simply using it for wrapping parcels.
If you are unsure of which grade of kraft paper is right for your needs, consult with a knowledgeable supplier who can help you choose the best option.
3. Determine Basis Weight / GSM
The first thing to consider when purchasing kraft paper is the basis weight / GSM.
The basis weight is the weight of a ream (500 sheets) of paper cut to the standard size. Basis weights can range from 33# to 270#. The most common basis weights for kraft paper are 40#, 50#, and 60#.
It’s important to know the basis weight because it will affect how much the paper costs as well as how it performs. Heavier basis weights usually result in a stronger sheet of paper that’s less likely to tear. Heavier weights are generally used for packaging and construction applications, while lighter weights are typically used for art projects or wrapping gifts. Keep in mind that a higher basis weight also means a higher price tag.
GSM stands for “grams per square meter” and is used outside of the US market.
The GSM of kraft paper is an important metric because it affects the strength and durability of the paper. For example, a heavier paper with a high GSM will be more resistant to tearing and creasing. In contrast, a lighter paper with a low GSM will be more susceptible to damage. Kraft paper is typically available in a GSM range of 35 to 250 GSM. The exact GSM will vary depending on the manufacturer and the intended use of the paper. For example, packing paper may have a lower GSM than construction paper. Knowing the GSM of kraft paper can help you select the right product for your needs.
4. Know the Burst Factor or BF
The term “burst factor” or “BF” refers to the amount of force required to rupture a paper or board. It is an important property for industrial packaging applications such as shipping containers, drums, and sacks. The burst factor is measured by suspending a circular disc of paper or board from its center and gradually increasing the load until the specimen ruptures. The force required to rupture the specimen is then divided by its cross-sectional area to obtain the burst factor. For example, if it takes 200 pounds of force to rupture a disc with a cross-sectional area of 100 square inches, the burst factor would be 2 pounds per square inch. Kraft paper has a relatively high burst factor due to its dense network of fibers. This makes it an ideal material for strong, durable shipping containers and sacks.
The high bursting factor (BF) kraft paper usually ranges between 60 to 200 GSM and their BF range is generally between 18 and 35.
A balance between the BF and GSM determines the quality kraft paper for its intended use.
Other Kraft Paper Properties to Consider:
Tensile Strength of Kraft Paper:
The tensile force required to produce a rupture in a strip of paper or paperboard, measured in MD & CD, expressed in kN/m or PSI. Tensile strength is indicative of fiber strength, fiber bonding and fiber length. Tensile strength can be used as a potential indicator of resistance to web breaking during printing or converting.
Opacity of Kraft Paper:
Opacity is the measure of how much light is kept away from passing through a sheet. A perfectly opaque paper is the one that is absolutely impervious to the passage of all visible light. It is the ratio of diffused reflectance and the reflectance of a single sheet backed by a black body. The opacity of paper is influenced by thickness, amount and kind of filler, degree of bleaching and coating etc.
The higher the opacity, better the printability of kraft paper.
5. Think of Thickness or Caliper You Need
The caliper is the thickness of the paper expressed in thousandths of an inch. For example, a sheet of paper with a caliper of 4 has a thickness of 0.004”.
Kraft paper is available in a range of thicknesses or caliper and when selecting a caliper, keep in mind that thicker papers are more durable but also more expensive. Think about what you’ll be using the paper for and choose a thickness accordingly. If you’re not sure, it’s always better to err on the side of caution and choose a thicker paper rather than a thinner one.
6. Choose the Right Size
When purchasing kraft paper, you will have the option to buy it in rolls or sheets. Small rolls are ideal for craft projects and large rolls are better suited for industrial applications. If you plan to use it in a converting machine, buying it in rolls will be more efficient since you will be able to feed it directly into the machine without having to stop and reload sheets of paper constantly. If you do not have a specific application in mind or if you only need a small amount of paper or if you need it for wrapping smaller items, buying it in sheets may be more convenient since they’re easier to handle, store, and transport.
Beware of Variable Sizes:
When buying kraft paper, be sure to pay attention to sheet size. Some types of kraft paper are sold in standard sizes like 8.5” x 11” (22 x 28 cm), while others come in large rolls that can be cut to any desired width. Rolls typically range from 24-60” (61-152 cm) wide. If you need a specific size or dimension, make sure to verify if the supplier can offer it to you.
7. Consider Colors
Kraft paper is typically brown (unbleached), but it’s also available in white (bleached) and other colors such as golden, yellow, black etc.
The color you choose will depend on the application for which you’re using the paper. For example, white kraft paper is often used in food service applications because it provides an attractive backdrop for displaying food items. Brown kraft paper is more commonly used for construction or packaging applications where aesthetics is not as important.
If color is important to you, make sure to select the right shade before making your purchase.
8. Select the Right Finish
You will need to decide on the finish of the kraft paper. The right finish will depend on the specific application you have in mind for the paper.
Kraft paper can have either a glazed or unglazed finish. A glazed finish gives the paper a smooth surface, which makes it easier to print on. An unglazed finish gives the paper a rougher surface, which provides better grip and makes it less likely to tear. There are semi-gloss kraft papers too that have a slightly rougher surface texture than smooth papers, but still provide good printability.
9. Inquire About Customization Options
Some kraft paper manufacturers and suppliers may offer customization options to help their customers get exactly what they need. When requesting a quote, be sure to inquire about any customization options that may be available so that you can get a product that perfectly meets your requirements. Customization options may include size, basis weight or GSM, BF, printability, color matched edging, die-cutting, perforating, gluing, and more.
10. Compare Prices
The price of kraft paper varies depending on multiple factors, such as basis weight or GSM, BF, width, length, and quantity.
Whenever you’re making a purchase, it’s important to compare prices from multiple suppliers to get the best deal possible. This is especially true when purchasing kraft paper since there can be a wide range in prices depending on the supplier and the type of paper you’re looking for. By taking the time to compare prices, you can ensure that you’re getting the best value for your money.
When comparing prices, be sure to take shipping costs into account and any minimum order requirements.
Buying kraft paper in bulk will always be cheaper than buying it in smaller quantities. This is because sellers give discounts for large orders.
By doing your research and comparing prices, you can make sure you are getting the best possible deal on kraft paper.
11. Environmental Factors
Environmental factors are important to consider when choosing kraft paper. Kraft paper is made from wood pulp, making it a renewable resource. However, the process of manufacturing kraft paper is energy intensive and can release harmful chemicals into the environment. If you are buying bleached or white kraft paper, ask the manufacturers or supplier about the type of bleaching process used to make the paper. Also, to reduce the environmental impact of kraft paper, look for products that are made from 100% recycled materials or certified by a sustainable forestry program.
Conclusion
Purchasing kraft paper does not need to be complicated and we hope the above tips were helpful as you begin the process of sourcing kraft paper. Remember to always consider the grade, specifications, and customization options that are most important for your application to get the best possible product. With these factors in mind, you’ll be sure to find the perfect kraft paper supplier for your needs.