Everything you want to know about
packaging

Corrugated board consists of two or more flat sheets of paper (liners) with a wave-shaped sheet in between (fluting or medium). That sinusoidal fluted structure is no coincidence — the arch shape is one of the strongest geometric forms in nature. You see the same logic in bridge vaults and in the ribs of a leaf. Every flute trough and every flute crest functions as a small column that absorbs vertical pressure. This is how a box made of relatively light material can still carry hundreds of kilos.

The three layers of a standard corrugated board: outer liner (visible, printable), fluting (the corrugated middle sheet, which determines cushioning and stacking strength) and inner liner (in contact with the product). With double wall, a second flute layer and a third liner are added.

Kraftliner is made from fresh wood cellulose fibres (virgin fibres). Recognisable by its brown or white colour. Advantages: high tensile strength, superior moisture resistance, long fibre length. The right choice for export packaging, cold-chain logistics and heavy goods.

Testliner is largely or fully recycled. Its precise fibre composition and performance vary by grade and manufacturer.

White-top liner comes in two flavours: white-top kraftliner (virgin fibres + white top layer, strong and attractive) and coated white testliner (recycled + coating, cheaper). Both are ideal when printing or brand image matters — on brown board, colours always look more muted.

ECT (Edge Crush Test) measures the edgewise compression strength of the flat board material — how much force a strip of board can withstand on its edge. Expressed in kN/m. This is a material property: you test the unfolded board. ECT is the dominant quality benchmark in Europe.

BCT (Box Compression Test) measures the stacking strength of the finished, folded box. A press pushes down vertically until the box collapses. Result in Newtons (N). BCT is a system measurement: it includes the material, the box geometry, the glue quality and the ambient humidity.

Mullen test measures the bursting resistance — how much force is needed to puncture through the board wall. Relevant for products with sharp edges. In Europe largely replaced by ECT; still common in the US.

Research shows that the BCT under standard conditions can already have a variation of ±22% depending on liner quality and construction. Use the BCT as a guideline, not a guarantee.

Box dimensions are always specified as internal dimensions in the order L × W × H (length × width × height) in millimetres. The length is by definition the longest horizontal side.

The external dimension is larger. For each dimension you add twice the wall thickness:

This is essential for pallet optimisation — always work with external dimensions when you want to know how many boxes fit side by side. In addition, every box has a joining allowance (join factor) of around 30–40 mm for the side seam. That dimension is not included in the specified internal dimension, but is relevant when calculating the blank.

Going for a box in your exact dimensions? I work out flute grade, FEFCO style and die-cut for you — see custom cardboard boxes.

Flexo printing is the standard printing technique for corrugated board. A flexible relief plate (photopolymer plate) rolls over the board and applies ink. A separate plate is needed for each colour (a one-off cost, reusable thereafter).

The technical limits you should know:

The washboard effect — a visible ribbed structure beneath the printing — is not a printing fault but a substrate consequence. The tops of the flutes press harder on the liner than the troughs, which makes those points slightly different in colour. It is most pronounced with A- and C-flute and light colours. E-flute and preprint are the solutions if you want to avoid this.

Digital direct printing (inkjet) prints straight onto the finished box or blank. No plates, no setup costs, and you can add variable data per box (unique barcodes, numbering, personalised print).

The crossover point with flexo is usually somewhere between 500 and 2,000 units. Below that threshold, digital is almost always cheaper. Above it, flexo wins on unit price. In quality, digital direct printing is comparable to or better than flexo — but does not yet reach the level of preprint/offset at equal cost.

Compare all box printing techniques — including offset — on the printed boxes page.

EU Member States have a recycling target of 85% by weight for paper and cardboard packaging waste by 2030. This is a system-level target, not proof that every individual corrugated package is recyclable.

FSC and PEFC certification support the claim that virgin fibres (kraftliner) come from sustainably managed forests — neither label can guarantee this fully, but they provide independent checks on the origin. Relevant for companies with a green purchasing policy or for export markets and retail customers that require it.

The European PPWR (Packaging and Packaging Waste Regulation) entered into force on 11 February 2025 and has largely applied since 12 August 2026; other requirements are being introduced in phases. Among other things, it sets requirements for recyclability and for limiting unnecessary material and empty space. Corrugated board already largely complies — but composite materials (board with a plastic coating) are assessed more critically.

Tack is the immediate stickiness — how quickly the tape "grabs" on first contact. Adhesion strength (peel strength) is the force needed to pull the tape off after curing (24–72 hours).

Hotmelt has high tack but a lower ultimate adhesion strength than acrylic. For automated packaging lines, high tack is essential — the case sealer closes the box and the tape must hold immediately for the next step. For long-term storage, the ultimate adhesion strength matters more than the initial speed.

Choose R-PET when recycled feedstock fits your sustainability goals and the tape is technically suitable. R-PET does not make the complete packaging automatically PPWR-compliant.

In practice, both hand rolls and machine rolls almost always have a core diameter of 76 mm (3 inch) — by far the most common size for packaging tapes. The distinction lies purely in the roll length:

One machine roll of 990 m contains around 15 hand rolls. Fewer changes = fewer machine stops. When ordering, always check whether you are getting hand-roll or machine-roll options — the core is the same, but a hand roll in a machine leads to a high changeover frequency and higher cost per metre because of the short roll length.

The widths you meet in practice are 48 mm and 75 mm. The weight of the box decides, not the length of the seam: up to around 20 kg, 48 mm is enough; above that you move to 75 mm. So a long seam does not automatically call for wider tape — the overlap runs perpendicular to the seam. On a large but light box, an H-seal in 48 mm beats switching to 75 mm.

Yes. Printing on tape can be used for branding, colour coding, instructions or as a security measure. Two techniques:

Flexo printing: usually 1 to 3 colours (some suppliers and carriers support more), a repeat pattern, sharp colour results on a PP or R-PET carrier. The minimum order varies greatly by supplier — expect several thousand metres, and check the exact threshold with your supplier. Plate costs per colour are a one-off.

Digital printing: often plate-free and available in very small runs; conditions vary by product and supplier. The unit price may be higher at large volumes. Suitable for small runs, temporary campaigns or variable data.

Store rolls lying down or upright, in their original packaging, away from direct sunlight and heat sources. Ideal storage conditions: 15–25°C, maximum 60% humidity. Shelf lives:

After long-term storage, always test a sample before use. Tape that falls off the roll, turns whitish or loses its elasticity has lost its tack.

R-PET tape uses a recycled PET carrier instead of PP or PVC. This can support the use of recycled feedstock but does not make the complete packaging automatically PPWR-compliant. The box, adhesive, application, recycling route and supplier evidence remain part of the assessment.

R-PET, like PP, is available with several adhesive types: hotmelt for fast and cost-efficient packing at room temperature, or rubber/solvent for cold room, freezer or export use. In strength and printability, R-PET is comparable to PP. The cost is currently clearly higher than PP — this reflects the current tight availability of recycled PET raw material, and may ease as European supply grows.

Paper tape consists largely of fibre material but may also contain adhesive, coating or a plastic release layer. The 5% threshold in PPWR recital 13 is a classification rule for composite packaging; it does not prove that tape has no effect on paper recycling.

Limitations: less suitable for wet or cold environments, and less stretchable than plastic tape — which is why it is often reinforced with a fibreglass or cross pattern for extra tear resistance. There is also a fully paper, water-activated variant (gummed tape), which requires a moistening device but forms an even stronger, permanent bond with the board.

High-tack is an improved acrylic formula available as an upgrade to standard acrylic tape, usually at a higher price: faster adhesion on first contact and slightly better cold resistance than classic acrylic.

Compared to hotmelt or rubber/solvent, the tack of high-tack also remains less immediate. The familiar acrylic advantages are retained: quietest unwind, UV-resistant and colourfast (does not yellow).

Stretch film (stretch wrap, pallet film, wrapping film) is a transparent plastic film that envelops a pallet or bundle of goods and contracts as it springs back. No glue, no tape — only elastic memory.

The material is almost always LLDPE (Linear Low-Density Polyethylene), a plastic that stands out for its high stretchability, impact resistance and elastic recovery. LLDPE can be stretched 100–300% without tearing — ordinary polyethylene comes nowhere near that. That "memory" — the ability to return to its original length — is exactly what generates the containment force on the load.

Cast film is by far the most used type in Europe. Choose blown if you have loads with sharp corners, metal profiles or other puncture risk factors.

Pre-stretch means the wrapping arm stretches the film before applying it to the pallet, via two rollers in the wrapping head that turn at different speeds. The percentage states the final length: at 200% pre-stretch, 1 metre of film from the roll effectively delivers 2 metres of covering surface on the pallet, and at 300% (which modern machines can handle), 3 metres.

The financial benefit is direct: drastically less film per pallet, lower material costs, fewer roll changes.

With hand wrapping, in practice you reach 100–180% stretch — consistently achieving more is physically almost impossible to sustain. That makes the economics of hand wrapping fundamentally different from machine wrapping.

Not sure which film or wrapping setup fits your process? The full guidance is on the stretch film & tapes page.

Nano and multilayer film is often used at 12–15 µm for light, stable loads. This is not an automatic replacement: compare grams per pallet, containment force and load stability in a practical trial.

Black film is opaque. Purpose: theft prevention for valuable goods, and light UV protection for light-sensitive products. Downside: contents cannot be checked without removing the film.

UV-resistant film contains additives that strongly slow photodegradation from sunlight. Standard LLDPE film becomes brittle under prolonged UV exposure and loses its stretch. For outdoor storage longer than a few weeks, UV-stabilised film is not a luxury but a necessity.

Antistatic film contains additives that prevent electrostatic charge on the film surface. Standard stretch film builds up an electrostatic charge through wrapping — harmful to electronic components, semiconductors and dust-sensitive surfaces.

Coloured films (red, blue, green) are used for colour coding pallets by customer, department or product line.

Store rolls lying down (on the flat side) or upright, out of direct sunlight and away from heat sources and ozone. Note: ozone is released by electric motors and fluorescent lighting and degrades LLDPE over time.

Ideal storage: 15–25°C, dry. Shelf life of unused rolls: 12–24 months. After long-term storage, always pull out a test roll: if the film breaks easily or feels stiff, its flexibility has been affected and the roll can no longer be reliably used.

At IVX you have one dedicated point of contact: short lines, no rotating account managers, no call centre. It's deliberately set up so you can rely on it. We record your specifications and agreements in our system from day one, so your next repeat order looks exactly the same — for you and for us. And for production, IVX draws on a large international network of suppliers. IVX Packaging is a registered company: you work with a specialist, backed by a business that grows with you.