Covington GA & Sacramento CA
UNITED STATES
The short answer: void fill is a symptom, not a solution. Every cubic inch you fill by hand is a cubic inch you paid for in board, in freight, in dimensional weight and — from 2027 under state EPR programs — in producer responsibility fees. The right goal is not to fill the box but to eliminate the void by right-sizing the case and fitting the insert. Where genuine void remains, fitted fiber components beat loose fill on cost, damage and disposal.
Nobody designs a pack around void fill. It accumulates through three familiar decisions.
A standard case size is chosen from stock because it is available today, and it is 20% larger than the product. A product changes and the case does not, because changing the case means requalifying a pack. And a range of SKUs is consolidated into a single case size for simplicity, which means the smallest item in the range rattles in a box built for the largest.
Each decision is individually reasonable. The cumulative result is a packing station where an operator makes a judgment call about how much filler to add, hundreds of times a day, with no specification governing it.
| Cost line | How void drives it | Typical magnitude |
|---|---|---|
| Corrugated material | Larger case surface area | 8–20% of case cost |
| Void fill material | Direct | 2–10 cents per parcel |
| Labor at the station | Manual filling time | 3–8 seconds per parcel |
| Dimensional weight | Billed on cube, not weight | Often the largest single line |
| Trailer and container cube | Fewer units per load | 5–15% freight efficiency |
| Warehouse storage | More cube per SKU | Ongoing |
| EPR fees from 2027 | Assessed on packaging weight | Growing |
| Damage | Product still moves inside filler | Highly variable |
The last row is the one that surprises people. Loose fill does not immobilize a product; it surrounds it. A heavy item in loose fill settles to the bottom of the carton within the first hour of transit and then travels unprotected.
Right-size the case. This is the highest-value action and the one most often skipped because it requires touching the case specification.
The practical route is to audit your top twenty SKUs by volume, measure the actual product envelope, and compare it against the case in use. Operations doing this for the first time routinely find 30% to 50% of shipments running a case at least one size too large.
Where the case cannot shrink — because it serves multiple SKUs, or because a retailer specifies it — a fitted fiber insert converts unusable void into structure. A honeycomb block, a folded pad or a die-cut spacer immobilizes the product and carries stacking load, which loose fill never does.
Residual gaps around irregular products are a legitimate use for fill. The distinction is that it is closing a designed gap rather than compensating for an undesigned one.
Paper void fill. Recyclable in the same stream as the carton, no disposal burden on the customer, moderate material cost, higher labor than air pillows. Effective at closing gaps, poor at immobilizing.
Air pillows. Very low material cost and weight, fast to dispense, but they deflate under sustained compression, add a plastic waste stream at the customer, and sit in an unfavorable EPR tier.
Loose fill. Fast, cheap, and the least effective at immobilization. Products migrate through it. Also the most disliked by consumers, which matters in any channel where unboxing is visible.
Fitted fiber components. Higher material cost per unit, dramatically lower labor, genuine immobilization, single-stream disposal, and the ability to carry load. The right answer wherever volumes justify a designed part — which, with digital cutting and no tooling requirement, is a far lower threshold than it used to be.
US parcel carriers bill on the greater of actual weight and dimensional weight, calculated from cubic dimensions divided by a DIM divisor. For light products in oversized cartons, dimensional weight is almost always the billed figure.
The consequence is direct: a carton one size too large can cost more in a single shipment than the entire packaging bill of materials for that order. Across an e-commerce program, right-sizing typically returns more in freight than in packaging material by a factor of several.
Run one calculation to see where you stand. Take your ten highest-volume parcels, compute actual and dimensional weight for each, and identify how many bill on DIM. If more than a third do, right-sizing is your highest-return packaging project, ahead of any material substitution.
State producer responsibility programs assess fees on the weight and material type of packaging placed on the market. Void-filled packaging is penalized twice: once because the larger case weighs more, and again because plastic-based fills sit in a less favorable tier than fiber.
Right-sizing reduces the fee base directly. Converting from plastic fill to fiber components improves the rate. Both effects compound annually as fee schedules mature, and neither requires any change to the product.
A structured right-sizing exercise takes about eight weeks and does not require new equipment.
Weeks one and two: pull twelve months of shipment data and identify the SKU-to-case combinations representing 80% of volume. Measure the real product envelope for each rather than trusting drawings.
Weeks three and four: define a reduced case size matrix. Most operations can serve their volume with fewer case sizes than they think, provided each one is chosen deliberately rather than inherited.
Weeks five and six: design fitted inserts for the SKUs where a single case must serve several products. Digital cutting means prototypes in days with no tooling commitment.
Weeks seven and eight: test on real lanes, measuring damage and dimensional weight before and after. Both numbers should move, and if damage rises the insert design needs adjustment rather than the project being abandoned.
Three failure patterns recur.
Shrinking the case without adding an insert. A tighter case with the product still loose inside transfers handling force directly to the product. Right-sizing and fitting are one project, not two.
Too many case sizes. Optimizing every SKU to its own carton creates an inventory and station-complexity problem that costs more than the cube saved. Three to five sizes usually beats fifteen.
Ignoring the pallet pattern. A smaller case that palletizes worse can increase total cube. Always recompute the pallet pattern after a case change; this is the step most often skipped and the one that occasionally reverses the entire saving.
Void is no longer only a cost question. Several major US retailers and marketplaces now specify limits on empty space in shipping cartons, and enforcement has moved from advisory to chargeback.
Two programs matter most for e-commerce sellers. Amazon’s Frustration-Free Packaging and Ships in Own Container certifications both require the shipping container to be right-sized to the product, and both carry fee implications for non-compliant packaging. Club and mass retailers increasingly apply their own cube efficiency requirements to inbound freight.
The practical consequence is that right-sizing work done for cost reasons frequently satisfies a compliance requirement at the same time. Sequencing it that way — cost first, certification as a by-product — is usually easier to fund internally than the reverse.
Void fill is an operator decision made hundreds of times a day, and operator decisions are where variability enters a packing process.
Three changes reduce it. Provide a documented fill standard per SKU rather than leaving the quantity to judgment. Position fill material so the correct amount is the easy amount to grab. And measure the outcome: weighing a sample of outbound parcels against a target weight will quickly reveal stations that are over-filling.
Where a fitted insert replaces fill entirely, the variability disappears along with the labor — which is often the larger of the two savings on a fast line.
On disposal, customer perception and EPR treatment, yes. On material cost and dispensing speed, air pillows win. Neither immobilizes a product, which is why fitted components beat both where volume justifies them.
There is no single figure, but if void exceeds roughly a third of case volume, the case is the wrong size. Several state regulations and major retailer specifications are converging on limits in that region.
Use a fitted insert with variable cavities, or a small number of insert variants inside one case size. This preserves case standardization while eliminating the void, and inserts are far cheaper to vary than cases.
Only if the case is shrunk without adding fit. Done properly it reduces damage, because the product stops moving. The damage data should improve alongside the freight data; if it does not, the insert is wrong.
Filling a box is the most expensive way to solve a problem you should have designed out. Eliminate the void by right-sizing, fit what remains with designed fiber components, and fill only genuine residual gaps. The freight saving usually exceeds the packaging saving, and the EPR position improves at the same time.
Premier Packaging Products designs fitted fiber and honeycomb components with free design studies and no minimum order quantity, from Georgia and California. Ask us to look at your top ten cases.