The box is not just a container — it is the difference between a parcel that arrives intact and a damage claim you cannot win.
Box choice pulls in two directions at once. A smaller box costs less, because volumetric weight falls sharply with every centimetre removed. A larger box protects better, because there is more room for cushioning. The right answer is the smallest box that still leaves 5 cm of padding on every side of the contents.
Strength matters as much as size. Carrier networks are automated: parcels drop onto conveyors, get stacked several deep in cages, and sit under the weight of everything above them for hours. A box that feels solid on your kitchen table may not survive a 1.5 metre fall onto a metal roller or the compression load of a full cage.
Corrugated cardboard is not one material — the wall count changes what it can take.
| Type | Structure | Best for |
|---|---|---|
| Single-wall | One fluted layer between two liners | Light, non-fragile contents under about 5 kg — clothing, books, soft goods |
| Double-wall | Two fluted layers between three liners | Anything fragile, anything over 5 kg, and every international shipment |
| Triple-wall | Three fluted layers | Heavy machinery, dense goods over about 30 kg, and industrial parts |
| Padded poly mailer | Plastic film with bubble lining | Soft, unbreakable items — clothing, fabric, non-fragile accessories |
Take the length, width and height of the item, then add 10 cm to each dimension. That gives 5 cm of cushioning on every side — the working minimum for anything that can break.
Single-wall for light and robust. Double-wall for anything fragile, anything heavy, and anything crossing a border. When in doubt, go double-wall — the cost difference is small.
Reject any box with crushed corners, soft or bulging walls, water staining, or previous puncture damage. Used cardboard can lose up to half its compressive strength.
Automated scanners read whatever barcode they see first. An old label can route your parcel to a previous destination. Peel them off or black them out completely.
If the only box you have is far too tall, score the corners at the right height, fold the walls in and re-tape. That cuts volumetric weight without weakening the base.
Run tape along the centre seam, then across both end seams, on the top and the bottom. Use packing tape at least 5 cm wide — never masking tape, duct tape or string.
Seal the box and shake it. If you can hear or feel anything move, open it and add more void fill. Zero internal movement is the target.
Reusing a box that has already made a journey — its compressive strength is significantly reduced even if it looks fine.
Leaving empty space inside. Any void lets contents shift and strike the walls; this is the leading cause of in-transit damage.
Using a box that is far larger than needed and filling the gap with air. You pay for the volume and the contents still move.
Sealing with masking tape, duct tape, string or staples. Only pressure-sensitive packing tape holds under load.
Leaving old shipping labels or barcodes visible, which misroutes parcels on automated sorters.
Overloading a single-wall box. If the base bows when you lift it, the contents are too heavy for that grade of cardboard.
Relying on a 'Fragile' sticker instead of packing properly — automated sorting equipment cannot read stickers.
Buy boxes in two or three standard sizes rather than one — you will almost always ship cheaper with a closer fit.
Wrap each item separately when sending several in one box, so nothing can touch anything else.
For hollow items like vases and bottles, stuff the inside cavity with paper before wrapping the outside.
Foam peanuts settle in transit, so slightly overfill and press the lid closed rather than filling level.
Photograph the packed contents and the sealed box before it leaves — it is the evidence that supports any later claim.
For flat, framed or glass items, apply a large X of tape across the glass face before wrapping to hold shards together if it cracks.
You can, but understand the trade-off: corrugated cardboard loses a substantial part of its compressive strength after one journey, and up to about half if it has been damp or stored under load. For light, robust contents over a short distance it is fine. For anything fragile, heavy or international, use a new double-wall box.
Five centimetres on every side of the contents is the working minimum for anything breakable, which is why you add 10 cm to each of the item's dimensions when choosing a box. For genuinely fragile items, use the double-box method: an inner box cushioned inside a larger outer box.
Only if the extra space is filled with cushioning. An oversized box with air in it is worse than a snug one — the contents accelerate before they hit the wall. It also costs more, because you pay for volume. Snug plus properly padded beats large and empty every time.
Very little. Modern sorting hubs are automated and process parcels by barcode, not by sticker. Apply the labels anyway as a signal to the humans who do handle your parcel, but never treat them as a substitute for correct packing.
Some carriers accept them and many do not, and those that do usually require the item to be wrapped or bagged so that straps, handles and wheels cannot catch in the conveyor machinery. Check before booking, and expect the outer bounding dimensions to be used for pricing.
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