Stopping postal damage means designing for a network that sorts automatically and handles items many times. The practical fixes are restraint so the item cannot move, rigidity for anything that can bend, a closure that will not fail, and a format that fits the postal size bands rather than sitting awkwardly at the edge of one.
Postal networks are not gentle, and that is not a fault
A postal item goes through automated sortation designed to handle very large volumes quickly. It will be belted, slid, stacked, bundled with other items and handled several times by people moving at pace.
Specifying packaging that assumes careful handling is specifying packaging that will occasionally fail. The pack has to work in the system as it actually operates.
The four common postal failures
| Failure | Typical cause | Fix |
|---|---|---|
| Bent or creased | No rigidity in a flat pack | Board stiffener or book wrap |
| Scuffed or marked | Movement inside the pack | Restraint or a snugger format |
| Crushed | Stacked under heavier items | Rigid format or stronger board |
| Arrived open | Closure failure | Better adhesive, correct pattern, sealed format |
What goes wrong in the post.
Bending is the distinctively postal one - flat items in soft packaging are vulnerable in a way they are not in a parcel carton.
Rigidity for flat goods
Prints, documents, cards, photographs and flat products get bent because nothing in the pack resists bending. A paper mailer offers none.
A board-backed envelope or - better - a book wrap that grips the item and provides structure on both faces is the standard solution, and it frequently stays within letterbox depth. See postal and parcel packaging.
Restraint for small rigid goods
Small items in a padded mailer or a postal box move around and arrive marked. The fix is the same as for parcels: something that holds the item rather than surrounds it.
For small items a snugger format often does it; for anything fragile, a fitted insert. See protective packaging.
Closure in the post
Postal items get rubbed against each other and against machinery, which works at the edges of a seal. Self-seal mailers with a strong adhesive strip, or taped formats with the tape pattern specified, are what hold.
Check adhesive performance in cold weather if you despatch year-round - some adhesives are noticeably less effective at low temperatures.
Band fit helps protection too
A pack sitting awkwardly at the top of a size band tends to be handled as an exception, and exceptions get handled less predictably.
A format comfortably inside a band - particularly a letterbox-depth format - travels through the system more smoothly, as well as costing less and avoiding failed deliveries. See ecommerce packaging.
Practical steps
- Collect damaged items and sort by the four failures above.
- For bending, add rigidity rather than padding.
- For movement, make the format snugger or add restraint.
- For crushing, use a rigid format or a stronger board.
- For open packs, change the closure rather than adding tape over the top.
- Check the resulting format against postal depth and size bands.
The short version
- Postal sortation is fast, automated and handles items many times.
- Bending is the distinctively postal failure - add rigidity, not padding.
- Small rigid goods need restraint, not a bigger padded mailer.
- Check adhesive performance in cold weather.
- A format comfortably inside a band travels more predictably.
Frequently asked questions
Why do items get bent in the post?
Because nothing in the pack resists bending. Add rigidity - a board stiffener or a book wrap - rather than more padding.
Are padded mailers enough?
For small robust items often yes. For anything that bends, breaks or marks easily, they provide cushioning without structure or restraint.
Does writing 'do not bend' help?
Not reliably in automated sortation. Specify the pack as though the instruction will not be read.
Why do our mailers arrive open?
Usually adhesive performance - particularly in cold weather - or a seal that has been rubbed in sortation. Change the closure rather than adding tape over it.
Can a letterbox format still protect the item?
Yes, if you shrink by fitting rather than by removing protection. A book wrap grips the product and is frequently better than a loose item in a deeper pack.