Corrugated Flute Types A–F: Choosing the Right Flute for the Box

Corrugated board flutes are standardized by size — A, C, B, E, and F — with F-flute the thinnest (about 0.8 mm), per FEFCO, the European Federation of Corrugated Board Manufacturers. A-flute cushions best, C-flute is the shipping workhorse, B-flute balances print and stacking, and E and F flutes serve retail and folding-carton applications. The flute is the board's engineering core.

The Scenario: A core that sets performance

Flute selection faces three challenges:

Pain Points

• Heavy or fragile products need cushioning that thin flutes cannot provide;
• Retail packaging needs a flat printing surface that tall flutes cannot give;
• Stacking strength and board thickness must balance against shipping and storage costs.

The Solution: Three flute solutions

Three rules choose the flute:

1. Match flute to product weight Use A or C flute for heavy or fragile goods needing cushioning and stacking strength; B, E, or F for lighter products.

2. Match flute to printing needs Choose E or F flute where the box doubles as retail packaging needing a smooth print surface.

3. Balance thickness and cost Taller flutes cost more per meter and raise storage volume; thinner flutes pack tighter.

The Result: The right flute for the job

Every box gets the cushioning, stackability, and print surface its product and channel need.