Glossary
The language, without the mystique.
Packaging vocabulary is used as a filter far more often than as a tool. Here is the whole working lexicon of our trade, defined so that you can argue with a supplier on equal footing — including with us.
Ask about a term
If you have heard a term we have not defined, send it and we will add it.
Where it goes
Straight to the grading floor at 9869 Meeks Blvd, St. Louis, MO 63132.
Or email sales@reboxesmarket.com. We have no phone line — dimensions and counts survive much better in writing.
A USEFUL SHORTCUT
Not sure of the size?
Fold a box in the browser, read off the cube and pallet fit, and send the spec straight through.
- Basis weight
- The weight of liner or medium per thousand square feet. Higher basis weight generally means a stiffer, more durable sheet.
- BCT
- Box Compression Test. Measures the top-to-bottom load a complete erected box withstands before failing. The number racking engineers actually care about.
- BMC
- Box Maker's Certificate. The round stamp inside a box recording its construction, test rating, size limit and manufacturer.
- Bursting strength
- See Mullen test. Resistance to a diaphragm being forced through the board, in pounds per square inch.
- Caliper
- The thickness of the combined board, measured in thousandths of an inch.
- Case count
- The number of saleable units inside one shipping container. Drives the box size far more often than the product dimensions do.
- Combined board
- Liner and medium glued together — the finished corrugated sheet before it is cut into a box.
- Containment force
- How hard stretch film squeezes a pallet load. The thing you actually want; layer count is only a proxy for it.
- Corner board
- An L-profile strip placed over a container corner so strapping bears on the profile rather than crushing the board.
- Cube
- Volume. Erected cube is the container's internal volume; flat or knocked-down cube is what it occupies shipped flat, usually a ninth or less.
- Delamination
- Separation of liner from medium, usually from moisture. A delaminated box has lost most of its structural value and cannot be repaired.
- Die-cut
- Board cut to a custom profile with a shaped cutting die, rather than slotted on standard equipment.
- Die-line
- The flat blank — the unfolded outline of a box, showing cuts, scores and fold lines.
- Drop trailer
- A trailer left at your dock to be loaded or unloaded at your own pace, rather than a live load with a waiting driver.
- Dunnage
- Any material used to brace, cushion or fill void space around a product in transit.
- ECT
- Edge Crush Test. Measures the stacking strength of board in pounds per linear inch. The relevant number for palletised freight.
- FEFCO code
- A four-digit international code describing box style. 0201 is the common RSC; the first two digits give the construction family.
- Flute
- The wavy medium between liners. Designated A, B, C, E, F or N by height, and combined as BC or EB in double wall.
- FOL
- Full Overlap Slotted Container. Outer flaps overlap completely, adding edge strength — the best standard style for reuse.
- Freight class
- The NMFC classification that drives LTL pricing, substantially a density calculation. Empty corrugated rates badly because it is mostly air.
- Gaylord
- A pallet-sized bulk corrugated container, usually triple wall. Originally a brand name, now generic.
- GMA pallet
- The 48" × 40" Grocery Manufacturers Association pallet, the dominant North American footprint. Real examples run 47.5 to 48.5 inches.
- Grade
- Our four-point condition scale for used containers: A like new, B good with light wear, C usable with visible wear, D recovery only.
- Honeycomb
- Laminated paper cells forming a rigid structural panel. Replaces plywood in many dunnage and display applications at a quarter of the weight.
- Hoop stress
- The outward force a free-flowing load exerts on a container's walls. The reason octabins have eight sides rather than four.
- HSC
- Half Slotted Container. Flaps on one end only — effectively a tray, usually used with a separate lid.
- Interlocking
- Stacking pattern where layers are rotated so boxes straddle those below. Stable, but throws away roughly 55% of compression strength.
- ISPM 15
- International phytosanitary standard requiring heat treatment and marking of solid wood packaging crossing most borders. Corrugated is exempt.
- ISRI
- Institute of Scrap Recycling Industries, whose specifications define recovered paper grades including #11 and #12 OCC.
- Knocked down
- Shipped flat. A knocked-down gaylord takes roughly a ninth of the trailer space of an erected one.
- Lead board
- The outermost top and bottom deck boards at each end of a pallet. They take the fork entry and rack beam load; damage here is a reject.
- Liner
- The flat facing sheets on the inside and outside of corrugated board.
- Live load
- Loading or unloading a trailer while the driver waits. Faster to arrange, more expensive if your dock is slow.
- Manufacturer's joint
- The seam where the box blank is closed — glued, stitched or taped. Stapled joints survive reuse better than glued ones.
- Milk run
- A recurring multi-stop route that collects and delivers on the same pass. The cheapest freight available on a reuse programme.
- Moisture content
- Water as a percentage of board weight. Specification condition is 6 – 8%; above 15% a box should not be stacked, and the damage does not reverse on drying.
- MSF
- Thousand square feet. The unit paper and board are traded in.
- Mullen test
- Bursting strength in pounds per square inch. Measures puncture resistance rather than stacking strength.
- NPA / NXX
- Not packaging — area code and exchange code in a North American phone number. We validate both on our forms.
- OCC
- Old Corrugated Containers. The recycling commodity grade for used cardboard. Mill grades #11 and #12 are the usual specs.
- Octabin
- An eight-sided bulk container for free-flowing materials such as resin pellets or powders.
- Overhang
- Container proud of the pallet deck edge. Half an inch costs 15 – 20% of compression strength; an inch costs 30% and roughly three trips of life.
- Pinwheel
- A pallet pattern where boxes rotate around a central void. Highest stability, moderate strength retention.
- Prohibitives
- Material in a recovered paper bale that does not belong there — film, foam, metal, wax. Mills deduct for it or reject the load.
- Pulper
- The vessel at a paper mill where bales are agitated with water until the board disintegrates into slurry. Anything that does not break down here costs money later.
- Ragger
- A rotating rope in a pulper that pulls out long stringy contaminants — film, strapping, tape.
- Reconditioned
- A used container repaired at a bench — flap splices, patch panels, re-scoring, edge reinforcement — and then re-graded from scratch.
- Repulpable
- Claimed to break down in a standard pulper. Worth verifying with your actual recycler rather than accepting from a datasheet.
- Residual
- The fraction of inbound material with no reuse, conversion or recycling outlet. Ours runs around 6% and we publish what is in it.
- Reverse load
- Your outbound empties riding on a trailer that was returning empty anyway. Half the carbon and a fraction of the cost.
- RSC
- Regular Slotted Container. The standard box: all flaps the same length, outer flaps meeting in the middle.
- SCF
- Sectional Center Facility. The USPS sorting hub a three-digit ZIP prefix maps to — which is how ZIP prefixes map to states.
- Score
- A crease pressed into board to control where it folds. Cracked scores are a primary failure point in reused boxes.
- Slip sheet
- A thin sheet used in place of a pallet, handled with a push-pull attachment.
- Slotted
- Cut with straight slots on standard equipment, as opposed to die-cut. Cheaper and faster for standard shapes.
- Stringer
- The longitudinal members of a pallet that the deck boards fasten to. A cracked stringer at a fork notch is a safety reject.
- Telescoping lid
- A separate cap fitting over the outside of a container sleeve. Protects the top edge and removes repeated flap folding.
- Test liner
- Liner made predominantly from recycled fibre, as opposed to virgin kraft.
- Triboelectric charging
- Static generated when dissimilar materials separate after contact — why fine powders in a poly-lined container need antistatic film.
- Trips per container
- The number of complete use cycles a reusable container achieves. The single most useful metric in a box pool.
- Triple wall
- Three layers of fluted medium and four liners. The construction behind most gaylords, rated to 1,100 lb test.
- Utilisation
- The proportion of a trailer's usable cube actually filled. On empty packaging this maps almost linearly onto cost per unit.
- Void fill
- Loose or formed material filling empty space in a carton to prevent product movement.
- Wax coating
- Moisture-resistant treatment applied to produce board. Cannot be recycled in a standard OCC stream and has almost no outlet.
- Wicking
- Moisture drawn up through board by capillary action, typically from a concrete floor into the base course of a stack.
- Yard
- Our word for the whole operation: inbound, grading floor, repair bench, press, baling line and outbound, all under one roof.
One term to retire
“Used.”
On its own it is meaningless — it covers everything from a box that shipped once to one that has been rained on for a winter. Ask for a grade instead, with its definition attached. We publish ours.
BCT
Box Compression Test
BMC
Box Maker's Certificate
ECT
Edge Crush Test
FEFCO
European Federation of Corrugated Board Manufacturers
FOL
Full Overlap Slotted Container
GMA
Grocery Manufacturers Association (pallet)
HSC
Half Slotted Container
ISRI
Institute of Scrap Recycling Industries
ISTA
International Safe Transit Association
LTL
Less Than Truckload
MRF
Materials Recovery Facility
MSF
Thousand Square Feet
OCC
Old Corrugated Containers
OSC
Overlap Slotted Container
RSC
Regular Slotted Container
SCF
Sectional Center Facility
TAPPI
Technical Association of the Pulp and Paper Industry
TL
Truckload
WIP
Work In Progress
Standards
Fourteen references worth knowing by number.
Specifying packaging gets much easier once you can name the standard rather than describe the requirement. These are the ones that come up in our quotes and our customers' RFPs.
| Reference | Title | Why it matters here |
|---|---|---|
| ASTM D642 | Compressive resistance of shipping containers | The test behind box compression figures |
| ASTM D4727 | Corrugated and solid fibreboard sheet stock | Material specification for board itself |
| ASTM D5639 | Selecting corrugated box dimensions | How to specify L × W × H correctly |
| TAPPI T 811 | Edge crush test of corrugated board | The ECT number on a Box Maker's Certificate |
| TAPPI T 810 | Bursting strength of corrugated board | The Mullen number |
| TAPPI T 412 | Moisture in paper and paperboard | How moisture content is measured and deducted |
| ISTA 3A / 6 | Packaged-product performance testing | Transit simulation for parcel and distribution |
| ISO 12048 | Compression and stacking tests | International equivalent of ASTM D642 |
| FEFCO / ESBO code | International fibreboard case code | The four-digit style codes we quote against |
| ISPM 15 | Wood packaging phytosanitary measures | Why corrugated avoids an export compliance burden |
| ISRI Scrap Specifications | Recovered paper grade definitions | The #11 and #12 OCC specs we bale to |
| GRI 306 | Waste disclosure standard | The format our diversion statements fit |
| EPA WasteWise | Voluntary waste reduction reporting | Compatible reporting format on request |
| FDA 21 CFR 176 | Indirect food additives: paper and paperboard | Why used board cannot be direct food contact |
Strength ratings
Mullen and ECT, side by side.
Two tests measuring two different failure modes. The equivalences below exist because carriers historically specified Mullen — treat them as conversational rather than contractual, and pick the test that matches how your boxes actually fail.
| Mullen (burst) | ECT (stacking) | Wall | Max size sum | Max gross weight | Typical use |
|---|---|---|---|---|---|
| 125 lb | 23 ECT | Single | 40" | 20 lb | Light retail, folding-carton replacement |
| 150 lb | 26 ECT | Single | 60" | 40 lb | Small parcel, light goods |
| 175 lb | 29 ECT | Single | 65" | 50 lb | General light shipper |
| 200 lb | 32 ECT | Single | 75" | 65 lb | The standard single-wall shipper |
| 250 lb | 40 ECT | Single | 85" | 80 lb | Heavier single wall |
| 275 lb | 44 ECT | Single | 95" | 95 lb | Top of the single-wall range |
| 275 lb | 48 ECT | Double | 100" | 120 lb | Entry double wall — the reuse workhorse |
| 350 lb | 51 ECT | Double | 110" | 180 lb | Heavy distribution |
| 400 lb | 55 ECT | Double | 120" | 225 lb | Industrial parts |
| 500 lb | 61 ECT | Double | 140" | 260 lb | Heavy double wall, bulk bins |
| 600 lb | 67 ECT | Triple | 160" | 300 lb | Entry triple wall |
| 700 lb | 71 ECT | Triple | 165" | 600 lb | Export crating replacement |
| 900 lb | 77 ECT | Triple | 170" | 1,200 lb | Heavy bulk bins |
| 1,100 lb | 82 ECT | Triple | 180" | 2,400 lb static | Gaylord standard |
“Max size sum” is length plus width plus depth. Exceeding it voids the certification even if the box is physically capable, which matters in a freight claim.
Why we publish the vocabulary
Jargon as a filter
Packaging vocabulary is used to establish who is in the trade far more often than to communicate anything. A buyer who does not know whether their carrier specified ECT or Mullen, or what a FEFCO code is, or why inside and outside dimensions differ by more than an inch on triple wall, is much easier to over-charge.
We would rather compete on grading, repair and freight. So here is the entire working lexicon, defined plainly enough to argue with a supplier on equal footing — including with us.
The one term to retire
'Used.' On its own it covers everything from a box that shipped once in a dry trailer to one that spent a winter on grass behind a building. Ask for a grade instead, with its published definition attached. Ours is four points and written down precisely so it cannot drift generously over time.
The terms that actually change decisions
- ECT versus Mullen — two tests, two failure modes, and real money riding on which one your application needs.
- Knocked down versus erected — roughly a ninefold difference in trailer cube on bulk containers.
- Inside versus outside dimensions — the single most common sizing error in this trade.
- Trips per container — the only metric that tells you whether a reuse programme is actually working.
- Prohibitives and moisture — the two things that decide what a bale of OCC is worth.
Paper
The liners and mediums underneath every box.
Board specification starts one level below the box: which liner, which medium, at what basis weight. Basis weight is stated in pounds per thousand square feet.
| Grade | Basis weight | Fibre | Typical use | Note |
|---|---|---|---|---|
| Kraft liner 26# | 26 lb/MSF | Virgin kraft | Light single wall | Lowest practical outer liner |
| Kraft liner 33# | 33 lb/MSF | Virgin kraft | Standard 32 ECT outer | The commonest liner in North America |
| Kraft liner 42# | 42 lb/MSF | Virgin kraft | 44 ECT and double wall | Noticeably stiffer, better print |
| Kraft liner 69# | 69 lb/MSF | Virgin kraft | Triple wall outer | Gaylord-grade facing |
| Test liner 2 | 27 – 50 lb/MSF | ≥ 80% recycled | General shipper | Most recycled-content board |
| Test liner 3 | 27 – 50 lb/MSF | 100% recycled | Internal and bulk | Lower burst for the same weight |
| Mottled white | 35 – 42 lb/MSF | Mixed | Retail-facing print | White outer, kraft back |
| Semi-chem medium 26# | 26 lb/MSF | Semi-chemical | Standard flute medium | Highest stiffness per weight |
| Recycled medium 23# | 23 lb/MSF | 100% recycled | Economy flute medium | Common in test-liner board |
| Type | Where it is used | Water resistance | Recycling | Note |
|---|---|---|---|---|
| Starch (corrugating) | Liner to medium | Low resistance | Ideal | The standard bond in all corrugated board |
| Hot melt EVA | Manufacturer's joint, cases | Moderate | Tolerated | Fast set; brittle when cold |
| Cold-set PVA | Case sealing | Low | Ideal | Slow set, strong fibre tear |
| Water-resistant starch | Produce board | High | Good | Alternative to wax for damp environments |
| Pressure-sensitive | Tape, labels | Varies | Tolerated in small amounts | Residue downgrades grade A board |
| Stitching (staples) | Manufacturer's joint | Unaffected | Removed in the junk trap | Outlasts glue through reuse cycles |
Freight class
Why empty packaging rates so badly.
LTL pricing keys off density. Knocked-down corrugated weighs almost nothing and occupies a full pallet position, so it lands near the expensive end of a scale designed around weight.
| Class | Density | Typical commodity | Where packaging sits |
|---|---|---|---|
| 50 | 50+ lb/ft³ | Bricks, steel bar | Rarely packaging |
| 55 | 35 – 50 | Hardwood flooring | Dense palletised goods |
| 60 | 30 – 35 | Car accessories | Heavy cartoned goods |
| 65 | 22.5 – 30 | Bottled beverages | Full case packs |
| 70 | 15 – 22.5 | Food in cartons | Typical dense distribution |
| 85 | 12 – 15 | Crated machinery | Palletised assemblies |
| 92.5 | 10.5 – 12 | Computers, monitors | Cushioned electronics |
| 100 | 9 – 10.5 | Boat covers, canvas | Light bulky goods |
| 125 | 7 – 8 | Small appliances | Void-filled cartons |
| 150 | 6 – 7 | Auto sheet metal | Erected boxes start here |
| 175 | 5 – 6 | Clothing, couches | Knocked-down heavy board |
| 200 | 4 – 5 | Aircraft parts | Knocked-down double wall |
| 250 | 3 – 4 | Mattresses, plasma TVs | Knocked-down single wall |
| 300 | 2 – 3 | Wood cabinets, tables | Erected gaylords |
| 400 | 1 – 2 | Deer antlers | Erected light bulk |
| 500 | < 1 | Gold dust, ping-pong balls | Loose void fill |
Note the two rows that matter here: knocked-down board is class 150 – 250, erected containers are class 300 – 400. That gap is the entire argument for banding everything flat.
Carbon accounting
Where packaging shows up in your inventory.
Almost all of it is Scope 3, which is both the hardest category to influence and the one where reuse makes the largest single difference.
| Scope | Definition | Your packaging | Where we affect it |
|---|---|---|---|
| Scope 1 | Direct emissions from sources you own or control | Your own forklifts and trucks moving packaging | Our nine trailers and yard equipment |
| Scope 2 | Indirect emissions from purchased energy | Electricity for balers, compactors, lighting | Our press, baler and grading floor lighting |
| Scope 3, cat. 1 | Purchased goods and services | The embodied carbon of every box you buy | Where reuse makes the largest difference to you |
| Scope 3, cat. 4 | Upstream transportation | Freight bringing packaging to you | Reduced by knocked-down cube and reverse loads |
| Scope 3, cat. 5 | Waste generated in operations | What your dock sends to landfill or recycling | Our diversion statements report directly into this |
| Scope 3, cat. 12 | End-of-life of sold products | Where your packaging ends up after the customer | Reuse postpones this entirely |