Corrugated flute sizes: A, B, C, E and F explained
The flute is the wavy layer inside corrugated board. Its size decides how thick the board is, how well it prints and how much it can carry.
The common flutes
- F flute is very thin, close to paperboard. Used for small, premium retail boxes.
- E flute is thin and smooth with great print quality. The usual choice for mailer boxes and printed retail packaging.
- B flute is the all rounder for shipping boxes, with good crush resistance and decent print.
- C flute is thicker with more cushioning and stacking strength. Very common for shipping cartons.
- A flute is the thickest standard flute. Less common today, used where cushioning matters most.
Double and triple wall
Combine two flutes and you get double wall board, usually BC (a B flute and a C flute) or EB. It stacks far higher and carries much more weight. Triple wall adds a third flute for bulk bins and very heavy goods.
How to choose
Start with the job. Printed mailer: E flute. General shipping box: B or C flute. Heavy items or tall pallet stacks: double wall. If you tell us the weight, size and how the box travels, we will pick for you.
Ready for a price? Send us your box size and quantity and we will reply with options and a production date.
