Get to Know the Different Flute Grades for Your Corrugated Boxes

The flute (the wavy part sandwiched between the liner) is what sets corrugated boxes apart from their cardboard cousin.

The flute size determines the thickness of the box walls and gives the box its stacking strength. Flutes are referred to by a letter that designates its size. They are measured by thickness and how many flutes per linear foot. Here are the most common flute sizes:

• A-Flute (33 flutes per linear foot) is the largest flute at 1/4” thick. Its thickness offers lots of protection and makes it a good option for fragile items.
  

• B-Flute (47 flutes per linear foot) is 1/8” thick. This is a lot thinner than A-flutes, but it’s deceptively strong. It’s often used for counter displays or canned goods. This flute is popular for die-cut designs.
  

• C-Flute (39 flutes per linear foot) is 3/16” thick. This is the one you’re probably the most familiar with, since it’s the most popular option for shipping boxes.
  

• E-Flute (90 flutes per linear foot) is only 1/16” thick, so it’s pretty thin. It doesn’t offer the strength of the larger flutes but does have some advantages. It’s sometimes used instead of paperboard for folding carton boxes. It’s efficient to store and is good for printing.
  

• F-Flute (125 flutes per linear foot) is 1/32” thick and is among the thinnest of the flute grades. It has a very smooth surface, so printed graphics will look sharp.
  

Combination of the above flutes are common, like BC-Flute, AB-Flute and EB Flute, etc.

If you want to know more about their commonly used functions, please contact our Sales Contact Immediately.

Contents are credit to refine packaging in the US.