Custom shipping boxes rated for the load you actually ship.
Regular slotted cartons and heavy-duty shippers in single- and double-wall corrugated, specified by edge crush test (ECT) and printed with your branding and handling marks.
- Specified by ECT, not guesswork
- Single- and double-wall options
- Flexo printing for 1–3 colors
- Minimum
- 100 units
- Single wall
- 32–44 ECT
- Double wall
- 48+ ECT
- Style
- RSC
- Board
- 32 ECT, B-flute
- 2-color flexo
- Size
- 18 × 12 × 10 in
ECT, burst and what they mean for you.
Corrugated boxes are rated in two ways, and both appear on the box maker’s certificate printed on the bottom flap:
- Edge Crush Test (ECT) measures how much force the board’s edge can take before crushing, in pounds per inch. It predicts stacking strength — the most relevant figure for modern parcel and warehouse handling.
- Mullen burst test measures the pressure needed to rupture the board’s face. It’s a better predictor of puncture resistance and rough handling.
The common rail-and-truck carrier tables (Uniform Freight Classification Rule 41 / National Motor Freight Classification Item 222) link the rating to the maximum weight of box plus contents:
| Single wall | Minimum ECT | Max weight of box + contents |
|---|---|---|
| Light duty | 23 ECT | 20 lb |
| Standard | 29 ECT | 50 lb |
| Most common | 32 ECT | 65 lb |
| Heavy | 44 ECT | 95 lb |
| Double wall | Minimum ECT | Max weight of box + contents |
|---|---|---|
| Standard | 42 ECT | 80 lb |
| Heavy | 48 ECT | 100 lb |
| Extra heavy | 61 ECT | 140 lb |
Parcel carriers have their own packaging guidelines, but 32 ECT single wall is the default for most e-commerce shipments, and 44 ECT or double wall is the step up for heavy or stacked loads.
Shipping box styles.
- Regular slotted container (RSC) — the classic cardboard box. All four flaps on top and bottom are the same depth, and the outer flaps meet in the middle. The most material-efficient style, and the cheapest to make.
- Half slotted container (HSC) — an RSC without top flaps, used with a separate lid.
- Full overlap (FOL) — outer flaps overlap the full width for extra stacking strength and a stronger base.
- Die-cut shippers — custom shapes with locking tabs, handles or built-in inserts; more expensive tooling, faster packing.
- Mailer-style shippers — see mailer boxes for the self-locking e-commerce version.
Shipping box specifications.
| Styles | RSC, HSC, FOL, die-cut shippers |
|---|---|
| Board | Single wall (B, C or E flute) and double wall (BC); kraft or white outer liner |
| Ratings | 23–55 ECT single wall; 42–82 ECT double wall |
| 1–3 color flexo; digital full color on short runs | |
| Marks | Logo, handling symbols, SKU/case labels, recycling marks |
| Delivery | Bundled flat on pallets; liftgate available |
Designing a shipper that saves money.
- Right-size to the product. Every extra inch adds board cost and can raise dimensional-weight charges.
- Let the box do the work. A fitted corrugated insert often replaces void fill — faster to pack and less waste.
- Think about the pallet. If cartons ship to a warehouse, size them to tile efficiently on a standard 48 × 40 in pallet without overhang.
- Print only what helps. One-color flexo branding plus handling marks is often enough; full color belongs on mailers the customer opens.
Frequently asked questions
What does 32 ECT mean?
It means the board withstands 32 pounds of force per inch of edge before crushing. Under the common carrier classification tables, a 32 ECT single-wall box is rated for up to 65 lb of box plus contents.
Should I choose ECT or burst-rated boxes?
ECT is the better indicator of stacking strength and is the modern standard for most shipments. Burst-rated boxes can be better for rough handling and puncture resistance.
When do I need double-wall boxes?
When contents are heavy (roughly 60 lb and up), very fragile, high value, or stacked high in storage. Double wall gives much greater compression strength.
Can shipping boxes be printed in full color?
Yes. Short runs can be digitally printed in full color; longer runs typically use 1–3 color flexo, which is cost-effective on corrugated.
What size pallet should I plan for?
The standard US pallet is 48 × 40 inches. We can size cartons to tile efficiently with no overhang.
Ship heavier, safer and cheaper.
Send the product weight, dimensions and how it ships. We’ll specify the ECT rating and size.