Product Guide

A, B and BC Flute Explained: What Strength Means for Packaging

A, B, and BC flute explained: choosing the right flute for your double wall boxes.

3 min readUpdated April 2025

Flute types

A-flute (5mm): largest flute. Maximum cushioning. Thickest profile.
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B-flute (3mm): medium flute. Good crush resistance. Better printing surface.
C-flute (4mm): between A and B. Good all-round performance.
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BC double wall: B-flute + C-flute combined. The standard double wall specification.

Quick answer

BC flute (B-flute + C-flute) is the standard double wall combination, providing excellent crush resistance and cushioning. The B-flute outer layer provides a smooth printing surface and puncture resistance. The C-flute inner layer provides cushioning and compression strength. Together they create a board approximately 7mm thick that holds items up to 25-30kg. AB flute is available for maximum cushioning where thickness is not a concern.

BC double wall

Best for printing and exterior durability.

Absorbs impacts and resists stacking loads.

Significantly stronger than any single wall option.

Suitable for heavy and fragile items.

Structure: board structure or weight limits.

How to choose

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BC flute: standard choice for most double wall applications
AB flute: maximum cushioning for very fragile heavy items
EB flute: thinner double wall for lighter items needing extra protection
From ProcuraPack

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Frequently asked questions

B-flute and C-flute combined. The standard double wall specification.

Approximately 7mm.

25-30kg in most box sizes.

For maximum cushioning on very fragile heavy items.

Yes, the standard for most double wall boxes.

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