A Guide To Understanding Corrugated Flutes (FREE Print-Out Included)

Posted by Bob Janik on Sep 6, 2022 8:00:00 AM


As a warehouse manager or operations professional, you understand the critical importance of using strong packaging materials when shipping products to customers.

Choosing the right box is often the first step in protecting your product. If the product arrives in good condition, everyone is happy and nobody thinks about the packaging. However, if the product arrives damaged, you are now under the microscope using valuable time to communicate and re-ship the product. Let us help.

Protection Starts with Corrugated Flutes

Sometimes a failure to protect the box contents is due to using the wrong packaging supplies. Although boxes can be used to ship everything, using a poorly reinforced box can lead to disastrous shipping results.

It is crucial for the buyer to carefully choose packaging so that the entire process will flow smoothly. Surprisingly enough, there are certain elements of engineering that go into the design of boxes and packaging elements. One of the simplest, but most effective forms of protection is corrugated flutes.

One of the most common uses of corrugated flutes are eCommerce and subscription services. Since the products can range in both shape and size, it's important to have a clear understanding of the different types of custom packaging available and their uses. As such, we've created the free guide below to give a more in-depth look at the customization available for eCommerce & subscription services: 

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What Are Corrugated Flutes & How Do They Work?

Packing designers have found that the best way to increase fiberboard strength is by adding what are known as corrugatedistock-1041014478 flutes.

If pressure is applied to the side of the board, the corrugated flutes (which are found as wave-shaped arches that are sandwiched between two linerboards) serve as a protective cushion. They serve a vital role in a corrugated boxes' ability to withstand crushing while also keeping the products inside safe by resisting pressure and bending from all directions

The flutes can also help protect the contents from sudden changes in temperature.

The distance between each flute is known as a flute profile, and indicates what type of functionality the box will have.

Corrugated Flute Sizing

The flutes themselves come in a variety of sizes, which serve a number of useful functions such as increased shipping strength, reduced storage space, and improved printability. Corrugated flute sizes include:

  • A Flutes:
    This flute profile has about 33 flutes per foot and is 3/16” in thickness. Its larger size generally provides greater strength and cushioning, and offers superior stiffness qualities compared to other flute profiles.

  • B Flutes:
    With about 47 flutes per foot and 1/8” of thickness, this size flute is perfect for protecting canned goods. Due to the increased number of times it contacts linerboard, it offers great puncture and crush resistance.

  • C Flutes:
    At about 38 flutes per foot and 5/32” in thickness, this is generally considered the most adaptable, all-purpose flute. C-flute is the standard for RSC-style boxes. It is commonly used for packaging products of all types such as food products, household goods, manufactured parts, and much more.

  • E Flutes:
    This size has about 90 flutes per foot and is 1/16” in thickness, giving it a greater crush resistance and a relatively flat surface which can be used for high-quality printing applications.

  • F Flutes:
    This flute has about 125 flutes per foot and is 1/32” in thickness. It was developed for small folding carton type boxes, and is perfect for retail packaging.

The printout below is meant for you to keep on hand for easy referencing -- making ordering shipping supplies easier than ever before.

CSP flutes table

Don’t forget: Flutes can also be customized to ensure optimum safety of your product during transit.

Wrapping Up

Hopefully this guide has helped give you a better understanding of corrugated flutes and their purpose in the shipping process. Feel free to print out the chart above for an easy reference to corrugated fluting profiles the next time you need to order corrugated boxes.

If you would like more information about custom flutes or other protective packaging? Contact us today or download our free Protective Packaging Consideration Guide below 

Download the Protective Packaging Guide

Editor's note: This article was originally published in March 2019, and has recently been updated.

Topics: Types of Packaging, Product Safety, Protective Packaging