Two buyers can order "a jumbo roll" and receive completely different objects. A roll is defined by six numbers, and if any one of them is unstated the order is open to interpretation — which is a polite way of saying someone will be disappointed at receiving.
Model guide · last verified 2026-10-21 · published in English · technical questions: contact the lab
Width. The finished slit width, in millimetres. Our master is 1,080 mm; anything narrower is produced by slitting, and widths that divide into 1,080 mm avoid edge trim.
Length. Running metres on the roll. Usually the number a buyer cares about, and the one that is not free to choose — see the next section.
Outer diameter (OD). The physical size of the wound roll. This is what decides whether the roll fits the unwind and the splicer, and it is what actually caps the length.
Core diameter (ID). The cardboard tube inside. 76 mm (3 inch) is the common standard on label presses; 152 mm (6 inch) appears on large rolls and some wide-web equipment. A mismatch here is scrap, not an inconvenience.
Winding side. Whether the adhesive faces in or out. Most label presses run adhesive-out with the liner outside; get it inverted and the web path is wrong.
Splice count. How many joins, if any, and whether they are flagged. A splice that arrives unannounced at line speed is a web break.
A wound roll is a spiral of constant thickness. The cross-section available to the web is the annular area between the core and the outer diameter, so the length follows directly:
Length = π × (OD² − ID²) ÷ (4 × thickness), with all dimensions in the same unit. In practice a wound roll comes out 1–3% shorter than the formula because of air entrapment and tension variation, so treat the result as a ceiling.
Put numbers on it. On a 76 mm core with 150 µm total thickness, a 300 mm roll holds about 441 m; 400 mm holds about 808 m; 500 mm about 1,279 m. Double the thickness to 200 µm and the same 400 mm roll holds about 606 m. Nothing about the customer changed — the geometry did.
This is why an enquiry that says "3,000 metres per roll" needs one more question: what outer diameter, and what does the unwind take? On a 76 mm core at 150 µm, 3,000 m requires an outer diameter of about 761 mm. Many presses cannot take that.
| Outer diameter | Core 76 mm, 150 µm total | Core 76 mm, 200 µm total |
|---|---|---|
| 300 mm | ~441 m | ~331 m |
| 350 mm | ~611 m | ~458 m |
| 400 mm | ~808 m | ~606 m |
| 450 mm | ~1,030 m | ~773 m |
| 500 mm | ~1,279 m | ~959 m |
Geometric values from Length = π(OD² − ID²)/(4t). Real rolls run 1–3% shorter because of air entrapment and tension variation. Use the roll calculator for your own figures.
The core is not a commodity detail. It sets the minimum bend radius of the web at the start of the roll, it determines what the unwind chuck can grip, and on a large roll it changes the tension profile as the roll pays down from full to empty.
76 mm is the default on label presses and on most converting equipment, and it is what most of our slitting produces. 152 mm cores are specified on very large jumbo rolls and on some wide-web equipment where the larger core reduces the tension swing across the run. If your machine has 152 mm chucks, say so at enquiry — it is a different core, not a different labelstock.
One more point that surprises buyers: a larger core does not only reduce the length available at a given OD, it can also improve the run. The first metres off a roll wound on a small core are tightly curved and can show curl memory at the die. If you are seeing curl in the first few metres of every roll, the core diameter is one of the things to look at.
A roll is wound from a finite run, so long rolls can contain splices. What matters is not whether a splice exists but whether you know about it before the web reaches the die.
The specification question is therefore three questions: how many splices per roll, are they flagged with a visible marker, and is the splice tape compatible with your process. A flagged splice lets the operator slow down, cut and restart. An unflagged one arrives at line speed and takes the die with it.
If the job cannot tolerate any splice — some security and pharmaceutical work cannot — say so at enquiry. That constrains the roll length, and it is better to agree a shorter roll up front than to discover a join mid-run.
Rolls are stored and shipped upright, on the end, never lying on the curved surface. A roll on its side has its own weight pressing on one line of the wrap for weeks; the result is a flat spot and adhesive ooze that shows up as a tension surge at the die long after anyone remembers how the roll was stored.
Keep them out of direct sun and away from heat sources. Film facestocks are dimensionally stable but the adhesive is not indifferent to heat, and a roll that has sat against a south-facing wall in summer is a different roll.
Humidity matters more for paper than for film, but it matters for both because the liner is usually glassine paper. A liner that has taken up moisture does not lie flat and the cut position drifts. Keep wrapped until use, and let a cold roll come to room temperature inside its wrapper before unwinding it — condensation on a cold liner causes as many registration problems as anything else on this list.
Ask about shelf life for the specific construction rather than assuming a number. It depends on the adhesive and the liner, and it is shorter than most buyers expect for removable systems.
1. Wrapper integrity. Any breach is a moisture path. Photograph it before opening and check the roll face at the damaged point.
2. Width. Measure at three points along the roll, not one. A slitting error shows as a taper.
3. OD and core. Confirm what you ordered. A core mismatch found after the roll is on the floor is expensive to fix.
4. Winding side. Adhesive out or in, matching the order.
5. Roll face. Look for telescoping (inner wraps slid out sideways), starring, and adhesive ooze at the edges. Telescoping does not recover.
6. Splices. Count them and check they are flagged.
7. First three metres. Peel a short length and check for adhesive transfer, blocking, and that the liner releases cleanly. This is the check that catches most problems while it is still the supplier's problem.
Width, core diameter, maximum outer diameter your unwind accepts, winding side, splice tolerance, construction code if you know it, and quantity in square metres. Add the application and the print process — those two fields catch most of the mismatches before they are quoted.
MOQ is 1,000 m², master width 1,080 mm, lead time 15–25 days depending on construction and slitting programme. Free A4 sample sets and TDS are available first, and the roll calculator will tell you what your required length does to the outer diameter before you commit to it.
Answered by the coating and conversion team, not by marketing.
Enter width, thickness and length to get area, outer diameter and weight — or work backwards from the OD your unwind accepts.
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