Packaging standards and terms

Grammage (GSM)

The weight of a sheet in grams per square metre, measured to ISO 536 or TAPPI T410. GSM drives stiffness, print behaviour and freight weight, and is normally quoted with a tolerance (commonly ±5%) that should be written into the purchase specification.

Cited in Printing for Packaging: A Complete Reference to Processes, Colour and Finishing, Rigid Box Types: Cardboard Set-Up Box Styles for Premium Packs and 11 more

Caliper

Sheet thickness in micrometres, measured to ISO 534 under a defined pressure and contact area. Caliper decides how board feeds, folds, scores and stacks on the converting line, so it is specified together with GSM rather than instead of it.

Cited in Printing for Packaging: A Complete Reference to Processes, Colour and Finishing, Adhesive and Release Liner Specifications for Labels and 7 more

Bulk

Volume per unit weight, calculated as caliper divided by grammage and quoted in cm³/g. A higher bulk gives a thicker, stiffer sheet at the same GSM, which is how mills deliver a bulky feel without adding weight.

Cited in Printing for Packaging: A Complete Reference to Processes, Colour and Finishing, Corrugated Box Types and Flute Grades: A Buyer's Guide and 3 more

FBB (folding boxboard)

Folding boxboard with mechanical pulp in the middle ply, usually coated on one or both sides and sold as GC1 or GC2 grades. It scores and folds cleanly at 200–400 gsm, which is why it is the default board for printed retail cartons.

Cited in Printing for Packaging: A Complete Reference to Processes, Colour and Finishing, Folding Carton Types: Styles, Board Choice and Buyer Decisions and 2 more

SBS (solid bleached sulphate board)

A fully bleached virgin fibre board with high brightness and a smooth coated surface. It carries high-quality print and food-contact grades, and rigid boxes and premium cartons normally use it between 250 and 450 gsm.

Cited in Printing for Packaging: A Complete Reference to Processes, Colour and Finishing, Folding Carton Types: Styles, Board Choice and Buyer Decisions and 1 more

Grey board (chipboard)

Uncoated recycled board that is grey throughout, made from about 1 mm to 3 mm and sold by thickness rather than grammage. In rigid boxes it supplies the structure while a printed wrap supplies the finish.

Cited in Printing for Packaging: A Complete Reference to Processes, Colour and Finishing, Rigid Box Types: Cardboard Set-Up Box Styles for Premium Packs and 4 more

Corrugated flute profile

The corrugated layer between the liners; the profile letter sets flute height, flutes per metre and the balance between stacking strength and printability. E-flute is about 1.5 mm, B-flute about 3 mm and C-flute about 4 mm.

Cited in Corrugated Box Types and Flute Grades: A Buyer's Guide, Project Walkthrough: From Brief to First Production Run for a Folding Carton and 4 more

Double-wall corrugated board

Two corrugated layers with three liners, used where a single wall cannot carry the load: about 6 mm for BC-flute and 10–15 mm for triple wall. It is specified by flute combination and ECT rather than grammage alone.

Cited in Corrugated Box Types and Flute Grades: A Buyer's Guide, Folding Carton vs Corrugated Box: Key Differences

Barrier coating (PE or PLA)

An extruded polyethylene or polylactic acid layer applied to board for moisture, grease or liquid resistance. Coating weight and coverage decide the barrier, and the coating also changes how easily the pack repulps.

PET window film

A polyester film patch glued behind a die-cut aperture so the product stays visible. Thickness of 12–15 µm is typical, and the film is specified together with its adhesive and food-contact status.

Cited in Printing for Packaging: A Complete Reference to Processes, Colour and Finishing, Folding Carton Types: Styles, Board Choice and Buyer Decisions

EVA foam insert

Ethylene vinyl acetate foam formed into trays and cushions for rigid boxes. Density and thickness set the cushioning, and it is usually laminated to paper so it can be wrapped like board.

Cited in Printing for Packaging: A Complete Reference to Processes, Colour and Finishing, Rigid Box Types: Cardboard Set-Up Box Styles for Premium Packs

Moulded pulp fitment

Wet-pressed recycled fibre formed into a shaped tray or fitment. It replaces foam and plastic inserts in many cartons and is specified by wall thickness and tolerance rather than grammage.

Cited in Rigid Box Types: Cardboard Set-Up Box Styles for Premium Packs, Corrugated Box Types and Flute Grades: A Buyer's Guide and 1 more

Face material (facestock)

The printable layer of a label — paper, film or foil — that carries the artwork. Its grade, coating and grain direction determine print quality, die-cutting behaviour and how the label performs when applied to a curved or squeezable surface.

Cited in Adhesive and Release Liner Specifications for Labels, Label and Sticker Specification Guide: Adhesive, Material and Surface

Release liner

The siliconised carrier sheet that protects the adhesive until the label is applied, and the surface the label is dispensed from on the applicator. Liner grade, caliper and release level must be matched to the dispensing speed and the label size.

Cited in Printing for Packaging: A Complete Reference to Processes, Colour and Finishing, Rigid Box Types: Cardboard Set-Up Box Styles for Premium Packs and 6 more

Silicone coat weight

The mass of silicone applied to the liner to set its release level, usually quoted in g/m². Too little gives an inconsistent release and liner lift-off; too much can transfer and stop the adhesive from anchoring.

Peel adhesion

The force needed to peel a label from a standard test plate at 180°, usually quoted in N/25 mm. FINAT FTM 1 and ASTM D3330 are the common methods, and the result depends on the test surface, dwell time and temperature, so figures are only comparable when the method is stated.

Cited in Adhesive and Release Liner Specifications for Labels, Label and Sticker Specification Guide: Adhesive, Material and Surface

Loop tack

The initial grab of an adhesive measured by bringing a loop of label into contact with a plate and pulling it away at a set speed. It predicts how well a label sticks on first contact, which matters on fast applicators and on cold or dusty surfaces.

Cited in Adhesive and Release Liner Specifications for Labels, Label and Sticker Specification Guide: Adhesive, Material and Surface

Shear (holding power)

The resistance of a bonded label to a constant load pulling it along the surface. Reported as time to failure under a standard weight, it shows whether an adhesive will creep or slide on a vertical or warm surface over months of service.

Release force

The force needed to separate the liner from the adhesive at a defined angle and speed, measured with methods such as FINAT FTM 3 and FTM 4. Set too low, labels lift off in the roll; set too high, high-speed lines suffer web breaks and mispicks.

Cited in Adhesive and Release Liner Specifications for Labels

Permanent adhesive

An adhesive formulated to build a bond that cannot be removed cleanly — the label tears or leaves residue if it is lifted. It is the default for product and logistics labels that must survive handling, moisture and time in storage.

Removable adhesive

An adhesive designed to release without damaging the surface or leaving a residue, within a stated time window. Promotion labels, price labels and re-closable packaging use it, but the removable window shortens as temperature and dwell time increase.

Die-cutting

Cutting the label shape with a rotary or flat die. On roll labels the cut is normally a kiss-cut that goes through the face material and adhesive but leaves the liner intact, so the web can keep running through the applicator.

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Dieline

The technical drawing of a pack — trim, crease, fold and glue lines — that the die is made from. Supplying artwork on the supplier's current dieline, instead of an older one, avoids creases landing on print and panels that no longer close.

Cited in Printing for Packaging: A Complete Reference to Processes, Colour and Finishing, Project Walkthrough: From Brief to First Production Run for a Folding Carton and 2 more

Bleed

Artwork extended beyond the trim line (commonly 3 mm) so that small cutting and folding shifts do not leave a white edge. Without bleed, a shift of a millimetre shows on the finished pack.

Cited in Printing for Packaging: A Complete Reference to Processes, Colour and Finishing, Project Walkthrough: From Brief to First Production Run for a Folding Carton and 1 more

Matrix stripping

Removing the surplus material between die-cut labels or carton blanks after cutting. How cleanly the matrix strips depends on face material, adhesive and die condition, and leftover slivers are a common cause of applicator jams.

Cited in Printing for Packaging: A Complete Reference to Processes, Colour and Finishing, Label and Sticker Specification Guide: Adhesive, Material and Surface

ΔE (colour difference)

A numeric measure of how far a printed colour sits from the approved target, measured with a spectrophotometer to ISO 13655 conditions. A tight ΔE tolerance agreed on the proof is what makes a reprint match the first run across sites.

Cited in Printing for Packaging: A Complete Reference to Processes, Colour and Finishing, Project Walkthrough: From Brief to First Production Run for a Folding Carton and 4 more

Spot colour

A pre-mixed ink printed as a separate station rather than built from process cyan, magenta, yellow and black. Brand colours and large solid areas are usually run as spot to hold a consistent tone and avoid the mottling of four-colour builds.

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AQL (acceptance quality limit)

The quality level that is the worst tolerable process average when sampling inspection is used, applied through ISO 2859-1 tables. The AQL, the inspection level and the sample size are agreed in the order before production, not after the goods are ready.

Cited in Printing for Packaging: A Complete Reference to Processes, Colour and Finishing, Project Walkthrough: From Brief to First Production Run for a Folding Carton and 4 more

ECT (edge crush test)

The compression strength of corrugated board measured on its edge, quoted in kN/m or lb/in. It is the board property behind a carton's stacking performance and is usually specified together with flute type and board grade.

Cited in Corrugated Box Types and Flute Grades: A Buyer's Guide, Project Walkthrough: From Brief to First Production Run for a Folding Carton and 2 more

BCT (box compression test)

The load a finished, empty box withstands when compressed top to bottom. Stacking height and warehouse humidity reduce the lab figure in service, so buyers usually design to a safety factor below the measured BCT.

Cited in Corrugated Box Types and Flute Grades: A Buyer's Guide

MOQ (minimum order quantity)

The smallest quantity a supplier will run for a given specification. MOQ is set by make-ready, minimum material purchase and machine time, so it moves when you change board grade, print method or finishing.

Cited in Printing for Packaging: A Complete Reference to Processes, Colour and Finishing, Packaging Pricing Models and Fee Structures Explained and 2 more

Landed cost

The full cost of goods delivered to your door: unit price plus freight, insurance, duty, handling and any inspection or storage charges. Comparing suppliers on landed cost rather than unit price is what makes quotes from different Incoterms comparable.

Cited in Rigid Box Types: Cardboard Set-Up Box Styles for Premium Packs, Total Landed Cost for Packaging: Freight, Duty and Storage and 3 more