Choosing the right flute for your shipping box

Flute is the wavy layer sandwiched inside corrugated board, and it does most of the structural work. The letter describes how tall and how frequent those waves are — not the quality of the board.

E-flute is roughly 1.5mm thick with fine, closely spaced waves. It prints beautifully, folds crisply and suits retail-facing mailers where the box is part of the brand experience.

B-flute steps up to about 3mm with more cushioning, making it the default for boxes that ship on their own. C-flute is thicker again and is what most master cartons and pallet-bound outers use.

Double-wall BC combines two profiles for heavy or stacked loads. It costs more per unit, but a single crushed pallet usually costs more than the upgrade across a whole run.

If you are unsure, send us the weight of a filled box and how high they stack on a pallet. That is enough to specify the board grade correctly on the first attempt.