Void fill gets bought by the bag and specified by guesswork, which is why so many parcels arrive either rattling or stuffed. The useful way to think about it is as a clearance dimension: how much material do you want between the product and each wall? Answer that, and both the fill quantity and the box size fall out of it.
Think in clearance per side, not in volume
If you decide on two inches of cushioning on every side, then your internal box dimensions are the product dimensions plus four inches on each of the three axes, since there are two sides per axis. That single decision sets your box. Two inches around fragile goods is a commonly cited industry starting point, and durable goods usually need considerably less. The right number for your product comes from dropping real packed samples, not from a chart.
Calculating the void you are paying to fill
- Work out the internal volume of the box: internal length x width x depth.
- Work out the product volume, or the volume of its bounding box if the shape is irregular.
- Subtract. What is left is the void volume, per parcel.
- Multiply by your annual shipments. That is the volume of air you are buying fill for every year.
A 12 x 10 x 8 in box holds 960 cubic inches. A product with a bounding box of 8 x 6 x 4 in occupies 192. The void is 768 cubic inches, four times the product itself, on every parcel.
Choosing a fill type
| Fill | Good at | Weak at |
|---|---|---|
| Paper, crumpled or cut | Blocking and bracing, recyclable, easy to store flat | Cushioning a heavy item on a long drop |
| Air pillows | Filling large voids with very little weight | Point loads, and they deflate if punctured |
| Bubble cushioning | Wrapping a surface directly | Filling a large void economically |
| Foam in place or foam pads | Heavy or fragile items, repeatable protection | Cost, and storage volume |
| Die cut corrugated insert | Immobilising a product with no loose material | Irregular shapes, and it needs tooling, which is included here |
The cheapest fill is the box you did not oversize
Every cubic inch of void costs three times: the fill material, the extra board around it, and the dimensional weight on the freight bill. Because the die and the plates are included on every order, a box cut to your product costs no more to tool than a near-standard size, so there is no tooling argument for shipping air. If you are running a range of products through one box size, price a second size against the fill and freight you would save.
When an insert beats fill entirely
If the product is consistent and the volume is there, a die cut insert removes loose fill from the operation completely. It is faster to pack, it looks better on opening, and it protects more predictably because the product cannot migrate. See insert packaging for the formats, and partition boxes for multi-cavity work.
Ordering
Minimum order is 100 boxes, from about $0.48 per unit at bulk volumes, confirmed on your written quote, with the die, the plates, design support, US shipping and a digital proof included. Turnaround is quoted per product in three lanes: rush (expedited production plus air freight), standard (air) and cost saver (sea), from about 7 business days in production plus 2 to 5 days for delivery.
Send your product dimensions and your current box size and we will quote a right sized box against your current fill spend. Request a quote to start.
