Plain-English definitions for box-nerd jargon.

Everyone in this industry uses initialisms like they’re supposed to be obvious. They aren’t. Here’s the decoder ring.

BC-flute: A doublewall combination of B-flute and C-flute. Good general-purpose flute for heavy shipping.
Bulk bin: Generic term for a large corrugated container. See gaylord.
Die-cut: A box or insert cut to a custom shape with a steel-rule die, rather than simply folded from a blank.
Doublewall (DW): Corrugated board with two flute layers sandwiched between three liners. Standard for most gaylords.
Dunnage: Any material used to brace, cushion or fill space around a product inside a box. Corrugated pads, air pillows, paper wadding.
ECT: Edge Crush Test. Measures the vertical compression strength of a board in pounds per linear inch. A 32 ECT board crushes at 32 lb/in.
Flute: The wavy middle layer of corrugated board. Common profiles include A, B, C, E and F from tallest to shortest.
FOL: Full Overlap — a box style whose flaps completely overlap for extra strength and crush resistance.
Gaylord: A large corrugated bulk container, typically pallet-sized. Named after the Gaylord Container Corporation which popularized them in the 1930s.
HSC: Half Slotted Container — an RSC without top flaps. Used as an open-top bin or with a separate lid.
Kraft: Unbleached, natural brown paperboard. Most corrugated is made from kraft pulp.
Liner: The flat outer sheet of corrugated board. A doublewall box has three liners (outer, middle, inner).
LTL: Less Than Truckload. A freight mode for shipments smaller than a full trailer, typically 1–10 pallets.
OCC: Old Corrugated Containers — the recycling industry term for used cardboard that will be baled and re-pulped.
Pallet: A wooden, plastic or corrugated platform used to handle and store boxes in bulk. Standard U.S. pallet footprint is 48" × 40".
RSC: Regular Slotted Container — the most common shipping box shape, with four top and four bottom flaps that meet in the middle.
Reverse logistics: The process of moving goods (or in our case, empty boxes) from their final destination back to the point of origin, reconditioning, or disposal.
Singlewall (SW): Corrugated board with one flute layer between two liners. Lightest and cheapest, used for most shipping cartons.
Slip sheet: A thin corrugated or plastic sheet used instead of a pallet with a push-pull forklift attachment. Saves storage space.
Triplewall (TW): Corrugated board with three flute layers and four liners. Used for heavy loads and many gaylords.
Wall: The layers of fluted board in a corrugated panel. Singlewall, doublewall, triplewall, quadwall.
A-flute: The tallest standard flute profile, ~5 mm. Best stacking strength and cushioning. Most common in gaylord and triplewall stock.
B-flute: A short flute profile, ~3 mm. Good for flat-crush resistance and detailed die-cutting. Common in inner packaging.
C-flute: The middle flute profile, ~4 mm. The default for most general shipping cartons.
E-flute: A very short flute, ~1.5 mm. Used in retail packaging where surface smoothness matters for printing.
F-flute: The shortest standard flute, ~0.8 mm. Used for high-graphics packaging that needs to look like a solid carton.
BOL: Bill of Lading. The shipping document signed by the driver and the receiver that establishes legal transfer of the goods.
METRC: Marijuana Enforcement Tracking Reporting Compliance — the seed-to-sale tracking system used by Colorado for licensed cannabis operations.
WMS: Warehouse Management System. The software that tracks inventory location, movement, and identity within a yard or warehouse.
EPA WARM: U.S. EPA's Waste Reduction Model. The standard methodology for calculating CO₂e avoidance from materials diversion.
ESG: Environmental, Social, Governance. The set of frameworks companies use to report non-financial performance to investors and regulators.
EPR: Extended Producer Responsibility. Regulatory frameworks that put end-of-life packaging cost onto the producers of the packaging.
Closed loop: A reuse program in which the same containers cycle between the same set of facilities for multiple trips.
Reverse logistics: The process of moving goods (or empty containers) from their final destination back to a previous point in the supply chain for reuse, refurbishment, or disposal.
Cube: In freight terms, the volumetric capacity of a trailer (length × width × height). A trailer that fills its weight limit before its cube limit is "weight out;" one that fills its volume first is "cube out."
Deadhead: A trailer driving without cargo. Considered a productivity and environmental failure mode in well-routed freight networks.
Diversion: In waste management, the act of routing material away from landfill toward reuse or recycling. The metric used in most ESG reports for waste reduction.
Doublewall (DW): See "wall." Two flute layers between three liners. Standard for most gaylord boxes.
FCL/LCL: Full Container Load / Less Container Load. The intermodal equivalent of FTL/LTL.
FTL: Full Truckload. Freight that fills an entire trailer.
Gummed paper tape: Water-activated reinforced paper tape. The preferred sealing tape for reuse-oriented operations because it recycles cleanly with the box.
Hazmat: Hazardous materials. Boxes that have carried hazmat require specialized disposal and cannot be reused.
ISPM-15: International standard for treating wood packaging materials to prevent the spread of pests across borders. Applies to wood pallets, not corrugated.
ISRI: Institute of Scrap Recycling Industries. The trade association that publishes the standard grading specifications for OCC and other scrap materials.
Linerboard: The flat outer paper layer of a corrugated panel. Usually kraft (unbleached brown) but sometimes bleached white.
Manufacturer’s certificate: A printed declaration on the bottom flap of a corrugated box stating the burst test, ECT, and load capacity ratings. Standard on new boxes; reclaimed boxes may still carry the original certificate even after multiple trips.
Medium: The fluted middle layer of a corrugated panel.
Mullen test: A burst-strength test, measured in pounds per square inch. Predates ECT but still used for some specifications.
OCC #11: The ISRI grade for "old corrugated containers, baled, contains 5% maximum of prohibited materials and outthrows." The most common bale grade in U.S. recycling.
OCC #12: A higher-quality OCC bale grade — double-sorted, cleaner, sells at a premium over #11.
Pallet jack: A manual or powered low-lift handling tool for moving palletized loads at floor level. Cheaper and simpler than a forklift.
Pulping: The process of breaking down corrugated fiber into a slurry that can be re-formed into new linerboard. Loses fiber length each cycle.
Quadwall: See "wall." Four flute layers and five liners. Used for very heavy or very rough applications, including export crating.
Reach truck: A type of forklift with extending forks, designed for narrow-aisle high-rack warehouses.
Shrink wrap: Plastic film that contracts when heated. Used to consolidate pallet loads. Different from stretch film, which uses tension instead of heat.
Stretch film: Plastic film with elastic memory, applied under tension to hold pallet loads together. The dominant pallet-binding method in modern logistics.
Supersack: A flexible intermediate bulk container (FIBC) — a giant woven polypropylene bag for holding granular materials. Common for malt and grain.
Tare weight: The empty weight of a container or vehicle, used to calculate net cargo weight.
Triplewall (TW): See "wall." Three flute layers and four liners. Used for heavy gaylord boxes and the heaviest shipping cartons.
Tipping fee: The per-ton charge a landfill or transfer station charges to accept waste material. A major component of disposal cost in most U.S. markets.
WAT: Water-activated tape. See "gummed paper tape."