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When discussions about packaging arise, it’s easy to get confused.
Take cardboard, for instance. When you think of cardboard, you might assume that it is just one type of packaging material, but there is more to it than that.
Cardboard is one type of material, and corrugated cardboard is another. They are often confused for one another but serve different purposes depending on the product.
In this post, we will explore the differences between cardboard and corrugated cardboard, go in-depth into the various aspects that make up corrugated cardboard, and their benefits and uses.
By doing this, we hope to help you decide what kind of packaging you need and how working with corrugated packaging companies can help ensure your product is packaged in the most appealing way for your valued customers.
Corrugated Boxes – An Overview
Before we start, let us dissect what exactly a corrugated box is.
The conventional corrugated box typically has three fiberboard layers.
The outer layers are called liner boards, and the wavy layer of paper in between is known as flute.
Corrugated sheets can also be doubled-up, combining different fluting grades to add extra protection.
However, the standard corrugated box is the most common shipping option as it already provides excellent protection and is relatively cost-effective.
In fact, 95% of all shipped products in North America use corrugated cardboard containers!
Corrugated vs. Cardboard – What’s the Difference?
So now that you know what a corrugated box is and how common they are, you may wonder what the difference is between corrugated and cardboard.
We’ve already mentioned that corrugated cardboard differs from cardboard, but let us unpack this topic further.
Cardboard is generally made of thick paper stock or heavy paper pulp and provides little protection during shipping.
It’s typically used for smaller product packaging and containers but can also be used as structural support inside the packaging to keep items from losing their shape during transit.
Corrugated boxes are different.
Recall earlier that corrugated boxes consist of three fiberboard layers: two liner boards and flute in the middle.
Corrugated boxes are among the best options whether your company is shipping out large packages or sending a few products.
Corrugated packaging is commonly used for shipping boxes, as corrugated sheets are sturdier, lighter and more durable than cardboard.
You can trust that products will remain safe in the packaging while also being able to design your package in a way that customers love!
Knowing this difference is essential in deciding what kind of packaging will work best for your products, but if you’re considering using corrugated boxes, a corrugated packaging company can work with you on the design and prototype process to create the right option for you.
Types of Paper Liners
Now, if you’ve decided that corrugated packaging is suitable for your product, let’s take an even closer look at the options available, starting with the types of paper liners.
Kraft Liners
Manufactured from softwood trees, Kraft paper consists of 70-80% “virgin” chemical pulp fiber, which results in a top paper grade that is very stiff and durable. Kraft paper is the most sustainable option out of all the types of paper available, but it is also the most costly.
Options for kraft liners include:
- Brown Kraft – Varying natural brown color depending on the different fibers used, the pulping process, and the location of the paper mill.
- White Top Kraft – very strong and affordable and offers excellent printing characteristics.
- Mottled Kraft – Also known as Oyster Kraft. It is similar to White Top Kraft but has a mottled appearance.
- Fully Bleached White – A white Kraft liner with a natural look. It is put through an additional bleaching process to create a white surface. This paper grade is not as environmentally friendly as unbleached Kraft.
Test Liners
Test paper is a less costly option than Kraft. This is due to a higher percentage of recycled fiber content, resulting in a less durable paper liner.
The higher recycled fiber content also makes the paper more difficult to print on, but it is very common to use Test paper as the inner liner board of a corrugated box.
Options for Test liners include
- Test 2 – Partly recycled liner paper.
- Test 3 – Fully recycled liner.
- White Top – A white-coated recycled liner.
- Oyster – A mottled test liner.
Flute Paper
For flute paper, Semi Chem, and Waste Based Fluting is available.
Semi Chem uses virgin fibers and a neutral sulphite semi-chemical process, while Waste Based Fluting uses 100% recycled fibers.
Flute Grades
Flutes are made of paper, just like the liner boards, but the difference lies in how they are constructed. They are corrugated-shaped and provide cushioning, strength and compression-resistant qualities to your package.
And not only are there different types of paper liners to choose from, but there are also different flute grades allowing for even more customization with how your product is packaged!
A-Flute – 1/4” is the first type of corrugated flute. This flute grade has the highest protection and cushion qualities. It is very good at handling compression and stacking and is often used for packaging fragile items.
B-Flute – 1/8”. This flute appears much thinner than others, but do not let its appearance fool you. B-Flute is quite strong and is typically used for counter displays and canned food products.
It also has a flatter surface for higher-quality printing and is excellent for die-cutting.
B-Flute has excellent puncture and crush-resistance properties while also consuming less space. It has excellent all-around performance for all types of packaging but is also commonly used as padding, dividers, partitions, and other forms of additional packing material.
C-Flute – 3/16” is flexible and one of the most versatile flute grades in corrugated boxes. It has average crush resistance, stacking strength, and printing properties. You have likely seen this type used for shipping boxes, but it is also used for packaging glass, dairy, and furniture products.
E-Flute – 1/16”
is not typically used for shipping. As one of the thinner flute grades, E-Flute is often used as an alternative for paperboard folding cartons.
E-Flute is thinner and more condensed to reduce the outer box dimensions, saving storage space. E-Flute has excellent compression strength, crush resistance, and a relatively flat surface for high-quality printing applications. You may use E-Flute for cosmetics, fragile glass, ceramics, and other small and delicate products.
F-Flute – 1/32” has protective qualities similar to E-Flute but with an even smoother surface for high-quality printing. It is common for you to use F-Flute for clamshell packaging in the US fast-food industry. But in Europe, this grade of corrugated fluting is a standard option for specialty and retail packaging.
Thickness Options and Quality Control Tests
Now that we’ve covered the different types of paper liners and flute grade options, it’s finally time to look at thickness!
Below is a summary of some of your thickness options, but before we go into more detail, we must first discuss different quality control tests to understand better what each thickness offers.
- Liner Board – The ‘face’ of the fiberboard sheet. You glue flute onto this board.
- Single Face – Consists of one liner board and glued flute visible on one side.
- Single Wall – The most common thickness. Two liner boards with fluted fiberboard glued in-between.
- Double Wall – Three sheets of liner board and two fluted fiberboards in-between.
- Triple Wall – Four sheets of liner board and three fluted fiberboards in-between. This option can withstand heavier weights up to almost 300 lbs!
Quality Control Tests
Corrugated boxes are subject to stress and impact during packing, shipping, and storage. Corrugated packaging aims to resist damage as much as possible to protect the products inside.
There are different ways to test the strength of corrugated material. But which test should you use when selecting material for your corrugated boxes?
Edge Crush Test is one of the essential tests for corrugated packaging.
As the name implies, force is applied perpendicular to the edge of the corrugated board until it buckles.
The results give manufacturers confidence that the material has the strength and durability required to handle heavy loads and stack resistance.
The resulting value is shown in pounds per linear inch of load-bearing edge and is reported in ECT ratings.
32 ECT is the most common for corrugated material.
The Flat Crush Test is also used and is similar to the Edge Crush Test.
This test applies force directly on the surface area of the corrugated fiberboard until the flute flattens and compromises its structure.
This test determines the compression and stacking resistance of the corrugated board required to carry heavy loads.
The Burst Test, otherwise known as the Mullen Test, challenges the durability of the corrugated fiberboard’s surface.
As the Flat Crush Test looks for compression resistance, the Burst Test determines the force required to puncture the liner board. The resulting value is given in pounds per square inch.
200# means 200 pounds per square inch of force applied to the face of the liner board.
The Water Absorption Test, otherwise known as the Cobb Test, determines the level of moisture the material can withstand and maintain its structural integrity.
Measuring the absorbency of the box surface is also essential because it may affect the printability of the box.
On the back surface, the same test indicates how well the liner will adhere to the fluting.
The Cobb Test begins by pouring a specific amount of liquid onto the material. The material then absorbs the liquid for a certain amount of time before being removed and examined.
Finally, the Ring Crush Test measures the compression of paper and board materials. A strip of paperboard with a standardized length and width is formed into a ring. Force is applied perpendicular to the paper’s edge until it buckles.
Single Wall
With a basic understanding of quality control tests, we can finally examine the thicknesses and what they offer.
Single-wall corrugated box styles vary in material strength and durability. This can be tested with the Edge Crush Test, as mentioned earlier.
Single-wall corrugated boxes can carry weights from 23 ECT to 55 ECT. It weighs less, and “weaker” single-wall corrugated boxes may hold up to a minimum weight of 20 lbs.
| SINGLE WALL | ||
| Max. Weight Box/Contents (lbs.) | Min. Burst Test (lbs. per sq. in) | Min. Edge Crush Test (lbs. per in. width) |
| 20 | 125 | 23 |
| 35 | 150 | 26 |
| 50 | 175 | 29 |
| 65 | 200 | 32 |
| 80 | 250 | 40 |
| 95 | 275 | 44 |
| 120 | 350 | 55 |
Double Wall & Triple Wall
Because there are at least two walls of corrugated sheets in this style of corrugated box, double-wall, and triple-wall boxes are, of course, more durable. The downside to this is that the box is less flexible.
However, this trait may be necessary for certain products in some cases.
Double wall boxes have three sheets of liner board with two corrugated fiberboards in between.
Triple-wall boxes have three stacked corrugated sheets and four liner board facings.
Although there are many combinations of flute grades for double-wall or triple-wall corrugated boxes, some industry standard combinations include
AC Flute – A combination of the two most protective corrugated grades. This is excellent if you need extra protection for harsh shipping and handling processes.
With A-Flute stacking and compression resistance, this combination is also a perfect storage option.
BC Flute – An excellent all-around performer, this combination provides high-level transit protection and is most often seen in shipping boxes.EB Flute – Provides superior transit strength and safety, while the outer E-Flute allows for an excellent high-quality printing surface.
| DOUBLE WALL | ||
| Max. Weight Box/Contents (lbs.) | Min. Burst Test (lbs. per sq. in) | Min. Edge Crush Test (lbs. per in. width) |
| 80 | 200 | 42 |
| 100 | 275 | 48 |
| 120 | 350 | 51 |
| 140 | 400 | 61 |
| 160 | 500 | 71 |
| 180 | 600 | 82 |
| TRIPLE WALL (minimum puncture test, oz. per in. of tear) | ||
| Max. Weight Box/Contents (lbs.) | Min. Burst Test (lbs. per sq. in) | Min. Edge Crush Test (lbs. per in. width) |
| 240 | 700 | 67 |
| 260 | 900 | 80 |
| 280 | 1100 | 90 |
| 300 | 1300 | 112 |
Box Maker’s Certificate
With types of paper liners, flute grades, quality control tests and thickness, we’ve covered a lot of information about corrugated boxes!
Now with the box maker’s certificate, we are almost done with our deep-dive into corrugated cardboard packages.
Have you ever picked up a box from Amazon or Uline, checked the bottom and found a circular stamp that looks like a nutrition facts label?
That is a box maker’s certificate, also called a BMC. It is a convenient and efficient way of describing some quick specifications about the box, and there are two versions: the ECT-Rated BMC and the Mullen-Rated BMC.
You will notice a few visible differences, but these two certificates provide the same information.
The Box Manufacturer on the outer ring indicates the company responsible for manufacturing your box.
Board Construction is the information displayed directly under where it says box certificate. This information tells whether the box is a single, double, or triple wall.
Minimum Combined Weight Facings is the total weight of the liner board used before the full liner board is cut and made into boxes.
Size Limit is the maximum outer dimensions of the box. This section is helpful to know for storage and shipping purposes.
Gross Weight Limit is the maximum weight allowed for the box and the items within.
Finally, City & State is located at the bottom of the label. It indicates the location where the box is constructed and shipped.
Benefits of Corrugated Packaging
If you’ve followed along until now, you may already understand some of the benefits of corrugated packaging, but these benefits are worth repeating!
Corrugated cardboard and corrugated boxes have seen enduring popularity because of the many benefits they offer and the relatively low cost of production.
Some of the main reasons for their popularity include
Protection: Corrugated is one of the best packaging options available for those seeking to protect their items during transit. It can handle the impacts of being moved around and shipped, and the cushioning offers much support.
Durability: Corrugated boxes are durable because of their protective features.
The boxes can withstand a lot of impact without damaging products inside and serves as an excellent barrier to the elements.
Environmentally friendly: Sustainability has become increasingly important, especially for packaging. Corrugated boxes are made of recycled fibers. They are also easily recycled, making them a better contender for sustainable packaging.
Customizable: Because of the many options available for raw materials and their environmental-friendliness, corrugated boxes are the best option for those looking for bespoke packaging, including printing.
The shape and thickness are easily customizable alongside graphics and surface printing.
But what are some of the industries that corrugated packaging works best for?
What Industries Benefit from Corrugated Boxes?
Many industries benefit from using corrugated packaging, especially e-commerce.
Depending on the size and shape of the packaging, shipping and mailing can be more manageable.
As discussed, corrugated cardboard and corrugated boxes can withstand a lot of the wear and tear that occurs during shipping, making them the safest option.
E-commerce businesses significantly benefit from corrugated packaging.
With the reliance on online shopping growing exponentially, companies have been opting for corrugated packaging to ensure their products arrive at their customers’ doorsteps in pristine condition.
Furthermore, corrugated packaging offers great versatility in printing capabilities allowing brands to stand out in the mail rooms of their customers.
Corrugated is also the best option for sustainability and recycling, as discussed above.
Customers want to be loyal to brands, but brands must also demonstrate some commitment.
By choosing sustainable packaging, you can build immense trust with the customer and add lots of value to your brand narrative.
Corrugated packaging enables you to develop customer relationships while doing good for the planet.
Corrugated boxes are eco-friendly, recyclable packaging options that still look great!
In fact, recycled corrugated is used to make clay-coated news back (paper grade), thereby giving it another life!
Here are some examples of corrugated packaging successes we’ve worked on to provide you with a better idea of what the end product looks like and possible uses for corrugated boxes.
1canoe2: High-quality branded corrugated boxes
Working with 1canoe2, Pakfactory developed unique packaging that was true to its brand and continued shipping products safely.
The digitally printed corrugated boxes were printed incredibly fast while allowing the brand total creative freedom to design the packaging as they saw fit.
The result? A beautiful package that created a fantastic experience for customers as soon as they received their products.
This is just one example of all the different ways to use corrugated packaging, but you can find more inspiration for corrugated packaging here to find the right fit for your product.
Corrugated packaging offers a host of benefits at a relatively low cost.
You can have a lot of creative freedom in designing the packaging precisely as you wish with this material, which can be a lot of fun.
With a good understanding of corrugated packaging, businesses have the power to establish brand credibility and an exceptional customer experience.
Contact a packaging specialist today to learn more about using corrugated packaging for your product!
