Stack of corrugated cardboard sheets

What Is Corrugated Cardboard?

What is corrugated cardboard? You might not know the answer offhand, but you’ve definitely seen it. In fact, you probably have some corrugated cardboard packaging in your home right now, perhaps collecting dust in the garage.

Consider that about 95% of goods in the U.S. are shipped in corrugated cardboard boxes, and they’re especially important to the food and beverage industry. So what exactly is it, and what makes it unique?

What Are Corrugated Cardboard Boxes?

Corrugated cardboard boxes are widely regarded as one of the best types of packaging for shipping.

Whereas standard cardboard consists of a single, ultra-thick paper stock, corrugated cardboard actually has three components: an inside cardboard liner, an outside cardboard liner, and a ruffled fluting in between. You know the kind: It’s the ultra-thick cardboard material with a flexible zig-zag layer in the middle.

Corrugated cardboard boxes are essential to our supply chain. In fact, corrugated cardboard packaging manufacturers were deemed essential businesses during the COVID-19 shutdowns of 2020, as home delivery became an even more crucial part of our daily lives.

What Is Corrugated Cardboard Made From?

As with many materials, corrugated cardboard is divided into different grades. While the inner and outer liners are pretty consistent across all grades of corrugated cardboard packaging, the fluting in the middle can vary in quality—and it’s rated on a scale of A to F. 

  • A flute is the gold standard. It has the thickest profile and the maximum cushioning for packaged goods that require the most support. It also contains the maximum reinforcement for boxes that are stacked on top of one another.
  • B flute is used predominantly for canned goods. It works well for automated packing lines and offers optimal support for most shipping operations.
  • C flute is the most commonly encountered grade. It’s used for fragile and heavy goods like glass and furniture. It actually has a greater thickness than the B flute, despite appearing third in terms of grade.
  • D flute, sometimes referred to as T flute, is thicker than E and F flute but not quite as thick as B and C. Available in lightweight and high-performance varieties, it provides a cost-effective alternative to C flute packaging.
  • E and F flutes are the least durable varieties available. They’re often used to ship low-weight retail items as their surfaces work well for printing.

Types of Corrugated Cardboard

In addition to the flute, you have to consider the type of board as well. Single-wall board is the most common type of corrugated cardboard packaging. It comprises a single layer of corrugated material (the flute) with a liner sheet on each side. When you receive cardboard packaging in the mail, this is usually the type of material you’re dealing with.

There’s also single-face board, which consists of a single sheet of liner attached to a corrugated layer of liner. It offers better cushioning for fragile items and is often sold in paper rolls. It may be recommended for glass and similar materials, and can be combined with other types of corrugated cardboard. For instance, you could wrap a fragile glass item into a roll of single-face corrugated paper and then secure it in a corrugated cardboard box for safe shipping.

More durable varieties of corrugated cardboard are also available. For instance, some manufacturers add extra liners to each side and multiple layers of fluting for additional cushioning, strength, and shock absorption. You can find double-wall boards and even triple-wall boards, which are often used for shipping industrial parts and heavy equipment.

What Is Corrugated Cardboard Good For?

A delivery man writing on top of a box

Corrugated cardboard packaging works well for shipping most types of consumer goods, including foods, beverages, glass items, heavy items (like furniture), and more. It’s the industry standard for several reasons:

Extremely Durable

With corrugated cardboard, you get a much heavier, more protective material than with pulp or paper stock alone.

Corrugated cardboard can withstand a lot of movement and abuse without getting damaged, and without damaging the contents of the box. It can endure rough road conditions, inclement weather, and other everyday hazards.

Environmentally Friendly

Arguably one of the greatest benefits of corrugated cardboard is its eco-friendliness. It’s reusable, biodegradable, compostable, and recyclable, and constructed without dyes or bleaches.

Lightweight and Strong

You don’t need a lot of heft to protect delicate items during shipping. The unique design of corrugated cardboard allows for reliable protection without adding unnecessary weight.

For example, many Gorilla Shipper clients rely on packaging that can ship glass wine bottles—which is about as delicate as it gets. They love our corrugated shippers because these sturdy boxes offer complete protection without the added weight.


Corrugated cardboard can be purchased in bulk at a lower cost than other types of packing and storage containers. In addition, its lightweight design helps reduce the cost of shipping your products.

What Is Corrugated Cardboard’s Biggest Downside?

Man opening a box with foam pellets

Conventional corrugated cardboard packaging does have its downsides. For instance, a typical corrugated box doesn’t reinforce or hold fragile items in place. Often, you need extra reinforcement in the form of Styrofoam, packing peanuts, or similar materials to ensure safe shipping.

Gorilla Shipper’s Hexaboxes, however, are different. That’s because our corrugated boxes have a patented design that can fully protect your products from vibration, compression, and falls from a height of 30 feet. Our corrugated shippers are certified by the International Safe Transit Association (ISTA) and recommended by UPS and FedEx for transporting fragile items.

Our Hexaboxes also feature an innovative six-sided design that’s specially crafted to accommodate the size and shape of wine bottles and beer cans. You don’t have to worry about delicate materials being jostled and damaged. Best of all, each shipper is 100% recyclable, biodegradable, and made in the USA.

Get the Best Corrugated Boxes from Gorilla Shipper

Now that you know the answer to the all-too-common question, “What is corrugated cardboard?,” consider what it could mean for your own shipping or storage needs. If you ship fragile items, corrugated cardboard packaging can improve your bottom line by reducing the risk of product damage and keeping your customers happy.

Do you ship wine, beer, condiments, or other fragile containers? Gorilla Shipper is the place to shop for the best bottle, jar, and can packaging. We not only provide the toughest corrugated cardboard boxes but you can also save when you buy more. Browse our products to find the right packaging solution for your needs. Have questions? Contact us now.