What is Corrugated Cardboard? Types, Thicknesses, Benefits, & More

Corrugated cardboard looks basic but its layers make it incredibly strong and useful for packaging. In this blog, I will explain what corrugated cardboard is, its main types and why it is widely used for packaging. Let’s get into this and explore.

What is corrugated cardboard?

Corrugated cardboard is a strong packaging material made from one or more fluted paper layers placed between flat liner sheets. Its wavy inner structure provides cushioning, strength and protection, making it suitable for shipping boxes, storage cartons and product packaging.

What is corrugated cardboard made from?

Corrugated cardboard is usually made from three layers of paper bonded together. It consists of two flat outer layers and one wavy inner layer. Each layer helps keep products safe during storage and shipping including:

Two flat outer layers: Also called linerboards, these form the smooth outer surfaces and provide strength.
One fluted inner layer: This wavy layer adds rigidity, cushioning and protection against impact.
Starch based adhesive: This glue bonds the fluted layer to outer linerboards.
Wood fibres: Softwood and hardwood fibres may be used to improve strength, durability and print quality.
Recycled paper fibres: Many corrugated boxes contain recycled material helping reduce waste and support sustainable packaging.

What are the common corrugated flute types?

Corrugated cardboard has flutes or wavy layers. Each flute type has a different thickness which affects the box’s strength, cushioning and print quality. The different types of corrugated flutes are:

A-Flute

A flute has a thickness of an approximate 1/4 inch. Gives good shock protection and cushioning, suitable for fragile, heavy and puky articles like glassware, electronics and heavy items.

Approximate carrying weight: 65–80 lbs (29–36 kg)

B-Flute

B-flute is about 1/8 inch thick. Thinner than A-flute yet with a good stacking and crush resistance. Typically used for canned goods, beverages, merchandising boxes and shipping boxes.

Approximate carrying weight: 50–65 lbs (23–29 kg)

C-Flute

One of the most popular types of C-flute which is exactly 3/16 inch approx 4mm. It offers a good balance of strength, cushioning and puncture resistance making it suitable for everyday shipping and storage.

Approximate carrying weight: 65–80 lbs (29–36 kg)

E-Flute

E-flute is approximately 1/16 inch thick. As it is thin, light and smooth, it is good for printed retail packaging, subscription boxes and small product cartons.

Approximate carrying weight: 10–20 lbs (4.5–9 kg).

F-Flute

F-flute is approximately 1/32 inch thick. It is primarily performed on light and small items like cosmetics, jewellery and electronics. The smooth surface also makes it amenable to good quality, high-res printing.

Approximate carrying weight: Up to 20 to 35 lbs (9 to 16 kg).

Common Corrugated Flute Combinations

Double-wall and triple-wall boards combine different flute profiles to improve cushioning, strength and print quality.

BC-Flute: Combines B-flute and C-flute for strong stacking, cushioning and puncture resistance.
EB-Flute: Combines E-flute and B-flute for good strength and a smooth, print-friendly surface.
AC-Flute: Combines A-flute and C-flute for extra thickness and cushioning for heavy or fragile products.

Board performance also depends on paper grade, box dimensions, product weight, stacking conditions and moisture exposure.

Main Types of Corrugated Cardboard

Corrugated comes in many different wall styles and thickness. They offer varying degrees of cushioning, protection and strength for different packaging requirements, shipping and storage applications. Here is a breakdown of types:

Single-Face Board

A single face board is a board with only one flat liner and one exposed fluted layer. Typically, it is 1mm to 5mm thick depending on the flute utilized.

A light and inexpensive material, frequently used to provide a wrapping to removable glass bottles, furniture components and other fragile objects to safeguard them from scratching and provide cushioning during storage or transit.

Single-Wall Board

The single-wall board is built of a single fluted layer sandwiched between two flat layers (liners) and typically ranges from 1.5 mm to 5 mm in thickness. This is the most widely-used style of corrugated cardboard and is commonly used by shoe stores and online retailers for delivering shoes, shirts and small accessories.

It is about 4 mm thick when used with C-flute, 3 mm with B-flute, 1.5 mm with E-flute and 0.8 mm with F-flute.

Double-Wall Board

The double-wall board has two fluted inner layers and three flat outer layers of board. It is normally 4 mm to 7 mm in thickness and shows more strength than the single-wall board.

It is typically found for kitchen equipment, computer hardware, delicate items and boxes with multiple items as a result of the boosted assistance.

Triple-Wall Board

The triple-wall board has three fluted layers and four flat liners. Under normal conditions its size is usually 9 mm to 15 mm thick according to different flute combinations.

It is an excellent alternative to the wooden crate for machinery and other industrial components, bulk items and large export product items.

What are the popular corrugated cardboard box styles?

There are various box styles produced from the corrugated cardboard for different packaging, shipping and display requirements. These are the in-demand and industry-standard styles:

Tuck Top Auto Bottom: For cosmetics, medicines, food products and heavier retail items.
Regular Slotted Container: Suitable for general shipping, moving, warehousing and e-commerce deliveries.
Full Slotted Container: Good for heavy products, appliances, automotive parts and industrial goods.
Tab Lock Roll End: Great for eCommerce, subscription boxes, cosmetics and smaller retail products.
One-Piece Folder Box: Ideal for frames, mirrors and other flat products, such as books and artwork.

What are the benefits of corrugated cardboard?

Corrugated cardboard is popular due to its strength, light weight and cost efficiency. It is a fluted layer in the middle that reflects protection from pressure, bump and movement during shipping.

Strong and Protective: Boxes are strong and prevent products from getting crushed or damaged due to the layered structure and good cushioning.
Lightweight: Corrugated cardboard offers protection while being light weight, potentially saving shipping costs.
Easy to Customize: This can be cut folded, printed and made into various shapes and sizes for many kinds of products.
Cost-Effective: Corrugated boxes are generally affordable to produce, store and transport making them suitable for both small and large businesses.
Recyclable: Most corrugated cardboard can be recycled when it is clean and dry making it a more environmentally responsible packaging option.
Easy to Store: Boxes can be stored flat for future use, thereby maximizing storage space in the warehouse, store and other storage areas.

How to choose the right corrugated cardboard?

Select the corrugated board according to the product, its weight and fragility as well as the shipping environments. Follow these steps to determine the appropriate corrugated cardboard:

Choose the Number of Walls: Select single wall board for light products, double wall for heavy items and triple wall for machinery or export shipping.
Choose the Right Flute: Choose A-flute for cushioning, B-flute for crush resistance, C-flute for strength and E-flute for lightweight retail packaging.
Review the Strength Rating: ECT shows stacking strength while the burst rating measures resistance to punctures and impact.

Frequently Asked Questions