Double-Wall vs Single-Wall Postal Boxes: Which Should You Choose?
Single-wall vs double-wall: which postal box construction protects your products best?
The key difference
Single-wall corrugated board has one fluted layer between two flat liners. Double-wall has two fluted layers separated by a flat liner in the middle, creating a significantly thicker and stronger board. The choice affects protection, weight, cost, and internal dimensions.
Quick answer
Single-wall postal boxes handle most items up to 5-8kg. Choose double-wall for items over 8kg, high-value fragile goods, or boxes that will be stacked on pallets. Single-wall is lighter and cheaper, making it the default for standard e-commerce. Double-wall prevents damage claims that would cost far more than the packaging premium.
Strength comparison
It resists stacking weight much better, critical for palletised or warehouse-stored shipments.
Two fluted layers absorb impact more effectively than one.
Quality single-wall B or C flute is perfectly adequate for the vast majority of postal shipments.
Cost implications
Double-wall boxes cost roughly 40-60% more per unit than equivalent single-wall. They also weigh more, increasing shipping costs on weight-based pricing. The economic justification comes from preventing damage: if your product damage rate drops from 3% to 0.5%, the box upgrade pays for itself many times over on valuable items.
Understand board grades: board grades explained or packing for maximum protection.
Which to choose
Postal boxes in single and double wall
Find the right wall construction for your products at ProcuraPack.
Browse postal boxesFrequently asked questions
Single-wall has one fluted layer (1.5-4mm). Double-wall has two (5-7mm), providing roughly double the compression and puncture resistance.
For items over 8kg, high-value fragile goods, or boxes that will be palletised and stacked.
Approximately 40-60% more per unit than equivalent single-wall boxes.
Yes, B-flute single-wall handles the vast majority of e-commerce shipments up to 5-8kg.
Yes, it is heavier, which increases costs on weight-based carrier pricing.
Part of our guide
Product Guide: Postal Boxes
Expert guides on postal boxes, from sizing and materials to branding and cost optimisation.
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