Roll label specifications: six fields that decide whether the roll runs

1. The short version: roll labels fail on the specification sheet, not on press

A sheeted label only has to match size and colour. A roll label also has to match a machine. The same 50 × 30 mm label will not load — or will apply upside down — if the unwind direction is reversed, the core is 36 mm off, or the roll is 20 mm too fat for the holder. Six fields on one page prevent a re-run.

2. The six fields every roll specification needs

3. Draw it — "left" and "right" are not enough

Unwind direction is the field most often lost in translation: the same words mean opposite things to different suppliers. Three steps settle it:

1. Pull a short length off the roll and lay it flat with the adhesive side up;
2. Sketch the label face on paper and draw an arrow to the edge that leaves the roll first;
3. Write "face out / face in" beside it and note "arrow = direction the applicator pulls".

Safer still: courier one roll (or a metre) of what you use now and say "match this". For automatic lines, a physical sample beats any wording.

4. Core and roll diameter: the two machine dimensions people forget

76 mm (3") is the default on automatic applicators; 40 mm appears on mid-size machines; 25.4 mm (1") on small labels and desktop printers. They do not interchange — a 40 mm core will not sit on a 76 mm mandrel. Roll diameter is limited by the holder and the rewind arm, and the liner thickness changes how much web fits: thicker liner, fewer labels at the same OD.

So three questions belong in the first email: what core do you run, what is the largest OD the holder takes, and what weight limit per roll. Once those are fixed, the count per roll follows (next section).

5. Set the count per roll with changeover maths, not habit

More labels per roll is not automatically better (weight, OD) and fewer is not either (changeovers). Run one day's volume through the arithmetic.

Four minutes is an example — insert your own stop, thread, register and test figures. The point is that the count per roll has a calculable cost either way.

The other hidden cost is tail waste: the last few labels on a roll are often scrapped because tension goes slack. Short rolls and frequent changeovers raise that percentage.

6. Multi-language rolls: one version, one roll

Exporting to Hong Kong, Macau or South-East Asia usually means two or three language versions of one product. On rolls, wind one language version per roll (or per set of rolls) and mark version and language on the roll label and the carton. Never mix versions within a roll — the applicator will not sort them for you. Where volumes are small, a shared layout with a blank panel plus variable data (inkjet or digital overprint) can cover the language variants, but check local minimum type sizes first; Indonesia, for instance, sets minimum type heights and has separate rules for bold allergens.

7. A specification sheet you can copy

Fill those twelve lines and a factory can quote and schedule without a third round of questions. Leave one out and the first order usually costs a week.

8. Six checks before the rolls ship

1. Hand-apply 3–5 labels from the first roll — direction, face, position;
2. Measure core ID and roll OD against the specification;
3. Run 20–30 labels to confirm the sensor catches every gap;
4. Check splice position and flag tape, and that neither lands on key copy;
5. Pull the last 10 labels on the roll for register and tension;
6. Mark the carton: product, version/language, labels per roll, roll count, production date.

Related reading: Five ways to verify a label supplier, Barcode labels that won't scan, Export packaging that survives shipping.

Figures quoted are common industry practice (cores of 25.4 / 40 / 76 mm, gaps of 2–3 mm, roll OD of 300–400 mm). Your applicator or printer manual governs the actual limits. We manufacture to the specification you give us; we do not rule on machine compatibility on the equipment supplier's behalf.