Dunnage is the material packed around goods to stop them moving, rubbing or absorbing shock whilst they travel. Airbags between pallets, foam inserts inside a carton, timber blocking in a container, the corrugated sheet between layers — all dunnage.
It is not the packaging itself. The box is packaging; what you put in the box around the product is dunnage. The distinction matters because they are usually bought by different people, and dunnage is the one that gets cut first when someone is looking for savings.
The word comes from shipping, where timber was laid in the hold to keep cargo clear of the bilges and stop it shifting in a swell. The principle has not changed.
What dunnage does
Stops movement. A load that shifts in transit arrives damaged, and in a trailer it can also become a safety problem when the doors are opened. Voids are the enemy — anything not filled will be filled by the goods moving into it.
Absorbs shock and vibration. Road and rail journeys apply constant low-level vibration and occasional sharp impacts. Rigid contact between a product and a hard surface transmits both.
Separates items. Keeps products from rubbing against each other, which is what causes scuffing, paint damage and abrasion.
Manages moisture. Raising goods off a container floor keeps them clear of condensation, which collects in shipping containers as they pass through temperature changes.
Spreads load. Layer pads let you stack heavier, because weight is distributed rather than concentrated on the corners of the cartons below.
The main types of dunnage
Air pillows and dunnage bags. Inflatable bags that fill voids. Small pillows go inside cartons; large dunnage bags go between pallets in a container or trailer. They are light, cheap, and inflated at the point of use so they take almost no storage space until needed. The large bags are the standard way to brace container loads.
Foam. Available as sheets, loose pieces, or moulded inserts shaped to the product. Moulded foam gives the best protection for fragile, high-value or oddly shaped items, and costs the most. Foam-in-place systems expand around the product in the carton, which suits low volumes of varied shapes.
Corrugated (cardboard). Layer pads, dividers, corner protectors and edge boards. Cheap, recyclable, and adequate for most general goods. Corner boards in particular do a lot of work for very little money — they stop stretch wrap crushing carton corners and let a pallet be strapped without damage.
Kraft paper. Crumpled or machine-crinkled paper used as void fill. Fully recyclable, which is why many operations have moved to it from plastic. Heavier than air pillows for the same volume, so it costs more to ship.
Timber. Blocking and bracing for heavy or irregular loads, especially in containers. Machinery, steel and anything on a skid is usually secured with timber. Remember that solid wood dunnage crossing borders falls under ISPM 15 and must be treated and stamped, exactly like a pallet.
Plastic. Reusable dunnage trays and separators, common in closed-loop automotive and manufacturing supply chains where the same parts move between the same two sites repeatedly. High initial cost, negligible cost per trip.
Bubble wrap. Familiar, effective for surface protection and light cushioning, poor at filling large voids economically.
Steel and strapping. Not cushioning but restraint — banding a load to a pallet or securing it to container walls. Usually used alongside cushioning dunnage rather than instead of it.
How to choose
Work from the journey rather than the product.
How far, and by what mode? A pallet going forty miles by road needs less than one going by sea to another continent, where it will face weeks of vibration, temperature swings and condensation. Sea freight is the harshest common mode and the one most often under-specified.
How fragile, and how valuable? The question is not what the product costs but what a damaged one costs you — replacement, return freight, the customer’s reaction, and the order you do not get next time.
What shape are the voids? Large empty spaces in a container need dunnage bags or timber bracing. Small gaps inside cartons need void fill. Using carton void fill to brace a container is expensive and does not work.
Is weight chargeable? On air freight, dunnage weight is freight cost. Air pillows and light foam earn their premium there.
Does it need to come back? Closed-loop routes justify reusable plastic. One-way shipments do not.
Who unpacks it, and what do they do with it? Dunnage that is difficult to remove slows down goods-in. Dunnage that cannot be recycled locally becomes a disposal cost for your customer, and increasingly they notice.
Getting the amount right
Both directions are expensive.
Under-packing shows up as damage rates, returns, replacement freight and claims. It is easy to spot because the cost lands visibly.
Over-packing is harder to see and often larger. It shows up as material spend, heavier shipments, larger cartons, more dimensional weight, slower packing, and disposal cost passed to the customer. Nobody files a complaint about excessive packaging arriving safely, so it persists for years.
A practical approach:
- Measure your damage rate by product and route rather than in aggregate. Damage is rarely spread evenly — it concentrates in a few lines on a few lanes.
- Test rather than estimate. Drop testing and vibration testing to recognised standards is not expensive relative to a recurring damage problem.
- Right-size the carton first. Most excess dunnage exists to fill a box that is too big. A better carton size costs nothing per unit and removes the void entirely.
- Review after a change. New product, new carrier, new lane — the packing that worked before may not.
Dunnage in containers vs parcels
The word covers two quite different jobs, and conflating them is how operations end up with the wrong material.
Container and trailer dunnage is about restraint at scale. A 40-foot container rarely fills exactly, and whatever space is left will let several tonnes of cargo build momentum. The tools are dunnage bags between pallet rows, timber blocking against the walls, load bars, and strapping to lashing points. The failure mode is dramatic: a load that shifts at sea can damage the container itself, and opening the doors on a collapsed load is genuinely dangerous.
A few container-specific points:
- Brace against the doors. The door end takes the worst of the forces during handling and is where collapses become visible.
- Floor protection matters. Container floors are wooden and often damp. Timber runners or slip sheets keep goods clear.
- Desiccants are dunnage too. Container rain — condensation forming as a container moves between climates — ruins more cargo than people expect, particularly with hygroscopic goods.
Parcel and carton dunnage is about cushioning a single item through an automated network where it will be dropped, thrown onto a conveyor, and buried under heavier parcels. The tools are void fill, foam, bubble and corner protection. The failure mode is quieter: one damaged item, one return, one unhappy customer.
The engineering question is different in each case. Containers are about preventing movement of mass. Parcels are about absorbing energy. Material that does one well often does the other badly, which is why buying a single dunnage solution for both usually means over-specifying one and under-specifying the other.
The sustainability shift
Dunnage has changed faster than most warehouse materials over the last few years, driven less by cost than by what customers and regulators will accept.
The direction of travel is away from mixed and plastic materials towards single-material, kerbside-recyclable options. Paper void fill has displaced loose-fill and bubble in a lot of e-commerce packing benches. Corrugated inserts have replaced moulded foam where the protection requirement allows it. Where plastic remains necessary, the shift is towards reusable rather than single-use.
Three things worth knowing before making a change:
- Single-material beats clever. A carton with paper void fill goes into one recycling stream. A carton with a foam insert, a plastic bag and a corrugated divider is technically recyclable and practically landfill, because nobody separates it.
- Lighter is not automatically better. Paper weighs more than air pillows, so switching increases freight weight and therefore emissions on long lanes. The right answer depends on your mode and distance, and it is worth actually calculating rather than assuming.
- Under-protecting is the worst outcome environmentally. A damaged item means a replacement manufactured and shipped, plus a return leg. That dwarfs the footprint of the packaging you saved. Reducing dunnage only helps if damage rates hold.
Extended producer responsibility rules in a growing number of markets now charge by packaging weight and recyclability, which turns this from a preference into a line of cost.
Where to go deeper
- What is a pallet — the platform the load is built on.
- What is shrink wrap — securing the load once it is stacked.
- Warehouse processes — where packing sits in the flow.
- What is reverse logistics — what happens when protection fails.
- Order fulfilment — the process dunnage is protecting the output of.
The one-line takeaway
Dunnage is whatever you pack around goods to stop them moving and absorb shock — choose it from the journey rather than the product, and remember that over-packing costs more than it looks because the cost is spread across materials, weight and disposal rather than arriving as a damage claim.
Frequently asked questions
What is the difference between dunnage and packaging? Packaging contains the product — the carton, the film, the bottle. Dunnage is the material placed around it to stop movement and absorb shock. In practice the terms overlap, but the distinction is useful because they serve different purposes and often come from different budgets.
What is the most common type of dunnage? Corrugated cardboard in its various forms — layer pads, dividers, corner boards — because it is cheap, recyclable and adequate for most general goods. Air pillows dominate e-commerce void fill, and dunnage bags dominate container bracing.
Does dunnage need to be heat treated? Solid wood dunnage crossing international borders does, under ISPM 15, and must carry the IPPC stamp. Non-timber dunnage — foam, corrugated, plastic, air bags — is exempt.
Is dunnage recyclable? It depends on the material. Corrugated and kraft paper are widely recyclable. Foam and bubble wrap often are not, at least not through domestic collection. This is a common reason operations move to paper-based void fill.
How much dunnage do I need? Enough that nothing moves when the carton or pallet is handled normally, with no significant unfilled void. Beyond that you are adding cost. Testing a sample shipment beats estimating.
What is a dunnage bag? An inflatable bag placed in the gap between pallets or cargo blocks in a container or trailer. Inflated on site, it braces the load against shifting during transit, and it is the standard solution for the large voids that container loading leaves.
Who is responsible for dunnage on an international shipment? It follows the Incoterm. Whoever is responsible for loading and securing the goods is responsible for the dunnage, and for ensuring any timber used meets ISPM 15. Disputes usually surface after damage, when the question of who packed the container becomes expensive.
Can dunnage be reused? Reusable plastic trays and separators are designed for it and are common in closed-loop manufacturing. Air pillows and corrugated can sometimes be reused once or twice, but their protective performance degrades and most operations find the handling cost outweighs the saving.
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