A common and costly misunderstanding is that a stronger box protects fragile goods. It rarely does. Most transit damage is not caused by the box wall failing — it is caused by the product moving inside the box, knocking against the walls, the corners, or its neighbours until something cracks. The real protection comes from what holds the product still: the insert. This guide compares the main insert types — corrugated, foam and moulded pulp — so you can stop the rattle and reduce your returns.

Why movement is the enemy

When a parcel is dropped, thrown onto a conveyor, or jolted in a van, energy travels through it. If the product is held snugly in place, that energy is spread and absorbed. If the product is loose, it becomes a projectile inside its own box, building up speed across even a small gap before it hits a wall. That is why a beautifully strong double-wall box with a loose product inside offers less real protection than a modest box with a well-fitted insert. Immobilise the product and you have solved most of the problem. Our piece on reducing e-commerce damage and returns makes the same case from the returns-cost angle.

Corrugated inserts and dividers

Corrugated inserts are die-cut or folded from the same board family as the box, shaped to cradle the product or to divide the space into cells. They are the workhorse of packaging protection and, for most products, the sensible default.

Strengths: inexpensive, light, and made from the same recyclable material as the box, so the whole parcel goes into one waste stream. They can be die-cut into cradles, platforms, corner protectors and honeycomb-style dividers. A partitioned divider is the classic solution for bottles, jars, candles and glassware, keeping each unit from touching its neighbours.

Limits: corrugated cushions less than foam against sharp, sustained shock, so for very delicate or high-value items it may need pairing with a snug fit or a soft wrap. But for the majority of goods, a well-designed corrugated insert is all the protection required — and it keeps the packaging fully recyclable, which matters if sustainability is part of your eco-friendly packaging story.

Foam inserts

Foam inserts — typically die-cut from polyethylene or polyurethane foam — are cut to the exact silhouette of the product, holding it in a precise recess. This is the presentation you see around cameras, instruments, medical devices and premium electronics.

Strengths: outstanding shock absorption, a precise custom fit, and a genuinely premium feel when the lid is lifted. For heavy, delicate or expensive items, foam is hard to beat on protection.

Limits: foam is the most expensive option, it adds weight, and — importantly — it is a plastic that does not recycle alongside the cardboard box. That complicates the recycling message and means the customer has to separate materials. Use it where protection genuinely demands it, not for show.

Moulded pulp inserts

Moulded pulp is made from recycled paper fibre pressed into a shaped tray — the material of egg boxes and increasingly of premium electronics and cosmetics packaging. It sits between corrugated and foam in both performance and cost.

Strengths: good cushioning, a custom-moulded fit, made from recycled fibre and fully recyclable and compostable. It has an appealing tactile, matte finish that reads as considered and sustainable, so it works well for brands that want protection and an eco-credible unboxing.

Limits: moulded pulp usually needs a custom mould tool, which makes it best suited to larger, ongoing runs rather than small one-offs. Its surface is less refined than foam and its detail less crisp than die-cut corrugated.

Choosing the right insert

  • Most products, best value, fully recyclable: corrugated inserts or dividers.
  • Fragile, heavy or high-value items needing maximum cushioning: foam.
  • Eco-credible protection at reasonable volume: moulded pulp.
  • Multiple units in one box (bottles, jars, cans): corrugated cell dividers.

A practical approach

Start with the least material that reliably stops the product moving, then test it. Pack a real unit, tape it up, and give it a good shake — if you can hear or feel movement, the fit is not tight enough. Better still, send a sample on a real courier route and open it at the far end. A little investment in insert design saves far more in replacements, refunds and the goodwill lost when a customer opens a broken parcel.

Getting the fit right in the first place

An insert can only hold a product still if the box around it is the right size to begin with. A box that is too large leaves the insert fighting to fill space it was never meant to fill, and a box that is too tight can bow or refuse to close once the insert is in. The two decisions belong together: size the box to the product plus its insert, not to the bare product. If you are working this out, our note on measuring a box correctly covers the clearances to allow for inserts and protective wrapping.

It also helps to think about assembly time. A moulded pulp or foam insert drops in as a single piece, which is quick for the packer; a multi-part corrugated divider may take a few folds to build. For most small businesses the corrugated route still wins on cost and recyclability, but if you are packing at speed, factor the seconds-per-box into the decision alongside the material price.

If you tell us what you are shipping, how fragile it is and how many go out, we will recommend the right insert honestly — including plain corrugated dividers where an expensive moulded solution would be overkill. See constructions and inserts in our portfolio, or request a quote and we will size the protection around your product.